Mark promise creation methods with CanGc (#33928)

* Add CanGc annotations to promise constructor.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Propagate CanGc arguments for Promise::new_in_current_realm.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Fix out-of-order entries.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Propagate CanGc from Promise::new.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Suppress clippy warning.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

* Formatting.

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

---------

Signed-off-by: Josh Matthews <josh@joshmatthews.net>

46 files changed, 390 insertions, 207 deletions

diff --git a/components/script/dom/audiocontext.rs b/components/script/dom/audiocontext.rs
index 620c8f754b8..c67d25ff014 100644
--- a/components/script/dom/audiocontext.rs
+++ b/components/script/dom/audiocontext.rs
@@ -140,9 +140,9 @@ impl AudioContextMethods for AudioContext {
     }
 
     // https://webaudio.github.io/web-audio-api/#dom-audiocontext-suspend
-    fn Suspend(&self, comp: InRealm) -> Rc<Promise> {
+    fn Suspend(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
         // Step 1.
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 2.
         if self.context.control_thread_state() == ProcessingState::Closed {
@@ -201,9 +201,9 @@ impl AudioContextMethods for AudioContext {
     }
 
     // https://webaudio.github.io/web-audio-api/#dom-audiocontext-close
-    fn Close(&self, comp: InRealm) -> Rc<Promise> {
+    fn Close(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
         // Step 1.
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 2.
         if self.context.control_thread_state() == ProcessingState::Closed {
diff --git a/components/script/dom/baseaudiocontext.rs b/components/script/dom/baseaudiocontext.rs
index 683ba99bf34..1907878b4c9 100644
--- a/components/script/dom/baseaudiocontext.rs
+++ b/components/script/dom/baseaudiocontext.rs
@@ -294,9 +294,9 @@ impl BaseAudioContextMethods for BaseAudioContext {
     }
 
     /// <https://webaudio.github.io/web-audio-api/#dom-baseaudiocontext-resume>
-    fn Resume(&self, comp: InRealm) -> Rc<Promise> {
+    fn Resume(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
         // Step 1.
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 2.
         if self.audio_context_impl.lock().unwrap().state() == ProcessingState::Closed {
@@ -480,9 +480,10 @@ impl BaseAudioContextMethods for BaseAudioContext {
         decode_success_callback: Option<Rc<DecodeSuccessCallback>>,
         decode_error_callback: Option<Rc<DecodeErrorCallback>>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         // Step 1.
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let global = self.global();
         let window = global.as_window();
 
diff --git a/components/script/dom/bindings/codegen/Bindings.conf b/components/script/dom/bindings/codegen/Bindings.conf
index 7aa0d6f0d36..5a802df98f9 100644
--- a/components/script/dom/bindings/codegen/Bindings.conf
+++ b/components/script/dom/bindings/codegen/Bindings.conf
@@ -20,41 +20,46 @@ DOMInterfaces = {
 
 'AudioContext': {
     'inRealms': ['Close', 'Suspend'],
-    'canGc':['CreateMediaStreamDestination', 'CreateMediaElementSource', 'CreateMediaStreamSource', 'CreateMediaStreamTrackSource'],
+    'canGc':['CreateMediaStreamDestination', 'CreateMediaElementSource', 'CreateMediaStreamSource', 'CreateMediaStreamTrackSource', 'Suspend', 'Close'],
 },
 
 'BaseAudioContext': {
     'inRealms': ['DecodeAudioData', 'Resume', 'ParseFromString', 'GetBounds', 'GetClientRects'],
-    'canGc': ['CreateChannelMerger', 'CreateOscillator', 'CreateStereoPanner', 'CreateGain', 'CreateIIRFilter', 'CreateBiquadFilter', 'CreateBufferSource', 'CreateAnalyser', 'CreatePanner', 'CreateChannelSplitter', 'CreateBuffer', 'CreateConstantSource'],
+    'canGc': ['CreateChannelMerger', 'CreateOscillator', 'CreateStereoPanner', 'CreateGain', 'CreateIIRFilter', 'CreateBiquadFilter', 'CreateBufferSource', 'CreateAnalyser', 'CreatePanner', 'CreateChannelSplitter', 'CreateBuffer', 'CreateConstantSource', 'Resume', 'DecodeAudioData'],
 },
 
 'Blob': {
     'weakReferenceable': True,
-    'canGc': ['Slice'], 
+    'canGc': ['Slice', 'Text', 'ArrayBuffer'], 
 },
 
 'Bluetooth': {
     'inRealms': ['GetAvailability', 'RequestDevice'],
+    'canGc': ['RequestDevice', 'GetAvailability'],
 },
 
 'BluetoothDevice': {
     'inRealms': ['WatchAdvertisements'],
+    'canGc': ['WatchAdvertisements'],
 },
 
 'BluetoothRemoteGATTCharacteristic': {
     'inRealms': ['ReadValue', 'StartNotifications', 'StopNotifications', 'WriteValue'],
+    'canGc': ['GetDescriptor', 'GetDescriptors', 'ReadValue', 'StartNotifications', 'StopNotifications', 'WriteValue'],
 },
 
 'BluetoothRemoteGATTDescriptor': {
     'inRealms': ['ReadValue', 'WriteValue'],
+    'canGc': ['ReadValue', 'WriteValue'],
 },
 
 'BluetoothRemoteGATTServer': {
     'inRealms': ['Connect'],
+    'canGc': ['GetPrimaryService', 'GetPrimaryServices', 'Connect'],
 },
 
-'CustomElementRegistry': {
-    'inRealms': ['WhenDefined'],
+'BluetoothRemoteGATTService': {
+    'canGc': ['GetCharacteristic', 'GetCharacteristics', 'GetIncludedService', 'GetIncludedServices'],
 },
 
 'CanvasRenderingContext2D': {
@@ -65,20 +70,25 @@ DOMInterfaces = {
     'canGc': ['AddColorStop'],
 },
 
-'DOMImplementation': {
-    'canGc': ['CreateDocument', 'CreateHTMLDocument'],
+'CustomElementRegistry': {
+    'inRealms': ['WhenDefined'],
+    'canGc': ['WhenDefined'],
 },
 
-'DOMParser': {
-    'canGc': ['ParseFromString'],
+'DOMImplementation': {
+    'canGc': ['CreateDocument', 'CreateHTMLDocument'],
 },
 
 'DOMMatrix': {
     'canGc': ['FromMatrix', 'FromFloat32Array', 'FromFloat64Array'],
 },
 
-'DOMQuad': {
-    'canGc': ['FromRect', 'FromQuad', 'GetBounds'],
+'DOMMatrixReadOnly': {
+    'canGc': ['Multiply', 'Inverse', 'Scale', 'Translate', 'Rotate', 'RotateFromVector','FlipY', 'ScaleNonUniform', 'Scale3d', 'RotateAxisAngle', 'SkewX', 'SkewY', 'FlipX', 'TransformPoint', 'FromFloat32Array', 'FromFloat64Array','FromMatrix'],
+},
+
+'DOMParser': {
+    'canGc': ['ParseFromString'],
 },
 
 'DOMPoint': {
@@ -89,12 +99,12 @@ DOMInterfaces = {
     'canGc': ['FromPoint'],
 },
 
-'DOMMatrixReadOnly': {
-    'canGc': ['Multiply', 'Inverse', 'Scale', 'Translate', 'Rotate', 'RotateFromVector','FlipY', 'ScaleNonUniform', 'Scale3d', 'RotateAxisAngle', 'SkewX', 'SkewY', 'FlipX', 'TransformPoint', 'FromFloat32Array', 'FromFloat64Array','FromMatrix'],
+'DOMQuad': {
+    'canGc': ['FromRect', 'FromQuad', 'GetBounds'],
 },
 
 'Document': {
-    'canGc': ['Close', 'CreateElement', 'CreateElementNS', 'ImportNode', 'SetTitle', 'Write', 'Writeln', 'CreateEvent', 'CreateRange', 'Open', 'Open_', 'Fonts', 'ElementFromPoint', 'ElementsFromPoint'],
+    'canGc': ['Close', 'CreateElement', 'CreateElementNS', 'ImportNode', 'SetTitle', 'Write', 'Writeln', 'CreateEvent', 'CreateRange', 'Open', 'Open_', 'Fonts', 'ElementFromPoint', 'ElementsFromPoint', 'ExitFullscreen'],
 },
 
 'DynamicModuleOwner': {
@@ -102,7 +112,7 @@ DOMInterfaces = {
 },
 
 'Element': {
-    'canGc': ['SetInnerHTML', 'SetOuterHTML', 'InsertAdjacentHTML', 'GetClientRects', 'GetBoundingClientRect', 'SetScrollTop', 'SetScrollLeft', 'Scroll', 'Scroll_', 'ScrollBy', 'ScrollBy_', 'ScrollWidth', 'ScrollHeight', 'ScrollTop', 'ScrollLeft', 'ClientTop', 'ClientLeft', 'ClientWidth', 'ClientHeight'],
+    'canGc': ['SetInnerHTML', 'SetOuterHTML', 'InsertAdjacentHTML', 'GetClientRects', 'GetBoundingClientRect', 'SetScrollTop', 'SetScrollLeft', 'Scroll', 'Scroll_', 'ScrollBy', 'ScrollBy_', 'ScrollWidth', 'ScrollHeight', 'ScrollTop', 'ScrollLeft', 'ClientTop', 'ClientLeft', 'ClientWidth', 'ClientHeight', 'RequestFullscreen'],
 },
 
 'ElementInternals': {
@@ -117,6 +127,10 @@ DOMInterfaces = {
     'canGc': ['DispatchEvent'],
 },
 
+'FakeXRDevice': {
+    'canGc': ['Disconnect'],
+},
+
 'File': {
     'weakReferenceable': True,
 },
@@ -127,14 +141,17 @@ DOMInterfaces = {
 
 'GPU': {
     'inRealms': ['RequestAdapter'],
+    'canGc': ['RequestAdapter'],
 },
 
 'GPUAdapter': {
     'inRealms': ['RequestAdapterInfo', 'RequestDevice'],
+    'canGc': ['RequestAdapterInfo', 'RequestDevice'],
 },
 
 'GPUBuffer': {
     'inRealms': ['MapAsync'],
+    'canGc': ['MapAsync'],
 },
 
 'GPUDevice': {
@@ -144,11 +161,22 @@ DOMInterfaces = {
         'CreateShaderModule', # Creates promise for compilation info
         'PopErrorScope'
     ],
+    'canGc': [
+        'CreateComputePipelineAsync',
+        'CreateRenderPipelineAsync',
+        'CreateShaderModule',
+        'PopErrorScope'
+    ],
     'weakReferenceable': True, # for usage in GlobalScope https://github.com/servo/servo/issues/32519
 },
 
+'GPUQueue': {
+    'canGc': ['OnSubmittedWorkDone'],
+},
+
 'GamepadHapticActuator': {
-    'inRealms': ['PlayEffect', 'Reset']
+    'inRealms': ['PlayEffect', 'Reset'],
+    'canGc': ['PlayEffect', 'Reset'],
 },
 
 'History': {
@@ -159,8 +187,12 @@ DOMInterfaces = {
     'canGc': ['ReportValidity'],
 },
 
+'HTMLCanvasElement': {
+    'canGc': ['CaptureStream', 'GetContext'],
+},
+
 'HTMLElement': {
-    'canGc': ['Focus', 'Blur', 'Click'],
+    'canGc': ['GetOffsetParent', 'OffsetTop', 'OffsetLeft', 'OffsetWidth', 'OffsetHeight', 'InnerText', 'GetOuterText', 'Focus', 'Blur', 'Click'],
 },
 
 'HTMLFieldSetElement': {
@@ -175,6 +207,10 @@ DOMInterfaces = {
     'canGc': ['ReportValidity', 'SelectFiles'],
 },
 
+'HTMLImageElement': {
+    'canGc': ['Width', 'Height', 'Decode'],
+},
+
 'HTMLMediaElement': {
     'canGc': ['Load', 'Pause', 'Play', 'SetSrcObject'],
     'inRealms': ['Play'],
@@ -188,10 +224,6 @@ DOMInterfaces = {
     'canGc': ['ReportValidity'],
 },
 
-'HTMLCanvasElement': {
-    'canGc': ['CaptureStream', 'GetContext'],
-},
-
 'HTMLSelectElement': {
     'canGc': ['ReportValidity'],
 },
@@ -200,14 +232,6 @@ DOMInterfaces = {
     'canGc': ['Content'],
 },
 
-'HTMLElement': {
-    'canGc': ['GetOffsetParent', 'OffsetTop', 'OffsetLeft', 'OffsetWidth', 'OffsetHeight', 'InnerText', 'GetOuterText', 'Focus', 'Blur', 'Click'],
-},
-
-'HTMLImageElement': {
-    'canGc': ['Width', 'Height'],
-},
-
 'HTMLTextAreaElement': {
     'canGc': ['ReportValidity'],
 },
@@ -217,7 +241,7 @@ DOMInterfaces = {
 },
 
 'MediaDevices': {
-    'canGc': ['GetUserMedia'],
+    'canGc': ['GetUserMedia', 'EnumerateDevices'],
     'inRealms': ['GetUserMedia', 'GetClientRects', 'GetBoundingClientRect'],
 },
 
@@ -243,6 +267,7 @@ DOMInterfaces = {
 
 'NavigationPreloadManager': {
     'inRealms': ['Disable', 'Enable', 'GetState', 'SetHeaderValue'],
+    'canGc': ['Disable', 'Enable', 'GetState', 'SetHeaderValue'],
 },
 
 'Navigator': {
@@ -255,6 +280,7 @@ DOMInterfaces = {
 
 'OfflineAudioContext': {
     'inRealms': ['StartRendering'],
+    'canGc': ['StartRendering'],
 },
 
 'OffscreenCanvasRenderingContext2D': {
@@ -265,13 +291,21 @@ DOMInterfaces = {
     'canGc': ['GetTransform', 'SetStrokeStyle', 'SetFillStyle', 'SetShadowColor'],
 },
 
+'Permissions': {
+    'canGc': ['Query', 'Request', 'Revoke'],
+},
+
 'Promise': {
     'spiderMonkeyInterface': True,
 },
 
 'RTCPeerConnection': {
     'inRealms': ['AddIceCandidate', 'CreateAnswer', 'CreateOffer', 'SetLocalDescription', 'SetRemoteDescription'],
-    'canGc': ['Close'],
+    'canGc': ['Close', 'AddIceCandidate', 'CreateAnswer', 'CreateOffer', 'SetLocalDescription', 'SetRemoteDescription'],
+},
+
+'RTCRtpSender': {
+    'canGc': ['SetParameters'],
 },
 
 'Range': {
@@ -279,42 +313,46 @@ DOMInterfaces = {
     'weakReferenceable': True,
 },
 
-'Response': {
-    'canGc': ['Error', 'Redirect', 'Clone', 'Text', 'Blob', 'FormData', 'Json', 'ArrayBuffer', 'Headers'],
-},
-
 'Request': {
     'canGc': ['Headers', 'Text', 'Blob', 'FormData', 'Json', 'ArrayBuffer', 'Clone'],
 },
 
+
+'Response': {
+    'canGc': ['Error', 'Redirect', 'Clone', 'Text', 'Blob', 'FormData', 'Json', 'ArrayBuffer', 'Headers'],
+},
+
 'Selection': {
     'canGc': ['Collapse', 'CollapseToEnd', 'CollapseToStart', 'Extend', 'SelectAllChildren', 'SetBaseAndExtent', 'SetPosition'],
 },
 
 'ServiceWorkerContainer': {
     'inRealms': ['Register'],
-},
-
-'StaticRange': {
-    'weakReferenceable': True,
+    'canGc': ['Register'],
 },
 
 'ShadowRoot': {
     'canGc': ['ElementFromPoint', 'ElementsFromPoint'],
 },
 
+'StaticRange': {
+    'weakReferenceable': True,
+},
+
 'SubtleCrypto': {
-    'inRealms': ['Encrypt', 'Decrypt', 'GenerateKey', 'ImportKey', 'ExportKey']
+    'inRealms': ['Encrypt', 'Decrypt', 'GenerateKey', 'ImportKey', 'ExportKey'],
+    'canGc': ['Encrypt', 'Decrypt', 'GenerateKey', 'ImportKey', 'ExportKey'],
 },
 
 #FIXME(jdm): This should be 'register': False, but then we don't generate enum types
 'TestBinding': {
     'inRealms': ['PromiseAttribute', 'PromiseNativeHandler'],
-    'canGc': ['InterfaceAttribute', 'GetInterfaceAttributeNullable', 'ReceiveInterface', 'ReceiveInterfaceSequence', 'ReceiveNullableInterface'],
+    'canGc': ['InterfaceAttribute', 'GetInterfaceAttributeNullable', 'ReceiveInterface', 'ReceiveInterfaceSequence', 'ReceiveNullableInterface', 'PromiseAttribute', 'PromiseNativeHandler'],
 },
 
 'TestWorklet': {
     'inRealms': ['AddModule'],
+    'canGc': ['AddModule'],
 },
 
 'URL': {
@@ -322,12 +360,16 @@ DOMInterfaces = {
     'canGc': ['Parse', 'SearchParams'],
 },
 
-'VRDisplay': {
-    'inRealms': ['ExitPresent', 'RequestPresent'],
+'WebGLRenderingContext': {
+    'canGc': ['MakeXRCompatible'],
+},
+
+'WebGL2RenderingContext': {
+    'canGc': ['MakeXRCompatible'],
 },
 
 'Window': {
-    'canGc': ['Stop', 'Fetch', 'Scroll', 'Scroll_','ScrollBy', 'ScrollBy_', 'Stop', 'Fetch', 'Open'],
+    'canGc': ['Stop', 'Fetch', 'Scroll', 'Scroll_','ScrollBy', 'ScrollBy_', 'Stop', 'Fetch', 'Open', 'CreateImageBitmap'],
     'inRealms': ['Fetch', 'GetOpener'],
 },
 
@@ -338,11 +380,12 @@ DOMInterfaces = {
 
 'WorkerGlobalScope': {
     'inRealms': ['Fetch'],
-    'canGc': ['Fetch'],
+    'canGc': ['Fetch', 'CreateImageBitmap'],
 },
 
 'Worklet': {
     'inRealms': ['AddModule'],
+    'canGc': ['AddModule'],
 },
 
 'XMLHttpRequest': {
@@ -375,11 +418,16 @@ DOMInterfaces = {
 
 'XRSession': {
     'inRealms': ['RequestReferenceSpace', 'UpdateRenderState', 'UpdateTargetFrameRate'],
-    'canGc': ['End', 'RequestReferenceSpace'],
+    'canGc': ['End', 'RequestReferenceSpace', 'UpdateTargetFrameRate', 'RequestHitTestSource'],
 },
 
 'XRSystem': {
-    'inRealms': ['RequestSession', 'SupportsSessionMode'],
+    'inRealms': ['RequestSession'],
+    'canGc': ['RequestSession', 'IsSessionSupported'],
+},
+
+'XRTest': {
+    'canGc': ['SimulateDeviceConnection', 'DisconnectAllDevices'],
 },
 
 }
diff --git a/components/script/dom/blob.rs b/components/script/dom/blob.rs
index 71721104c4f..310a531a7da 100644
--- a/components/script/dom/blob.rs
+++ b/components/script/dom/blob.rs
@@ -257,10 +257,10 @@ impl BlobMethods for Blob {
     }
 
     // https://w3c.github.io/FileAPI/#text-method-algo
-    fn Text(&self) -> Rc<Promise> {
+    fn Text(&self, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
         let in_realm_proof = AlreadyInRealm::assert();
-        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
         let id = self.get_blob_url_id();
         global.read_file_async(
             id,
@@ -280,10 +280,10 @@ impl BlobMethods for Blob {
     }
 
     // https://w3c.github.io/FileAPI/#arraybuffer-method-algo
-    fn ArrayBuffer(&self) -> Rc<Promise> {
+    fn ArrayBuffer(&self, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
         let in_realm_proof = AlreadyInRealm::assert();
-        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
 
         let id = self.get_blob_url_id();
 
diff --git a/components/script/dom/bluetooth.rs b/components/script/dom/bluetooth.rs
index ce22ce26ad6..7a7bbf2e85d 100644
--- a/components/script/dom/bluetooth.rs
+++ b/components/script/dom/bluetooth.rs
@@ -30,7 +30,7 @@ use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::permissions::{get_descriptor_permission_state, PermissionAlgorithm};
 use crate::dom::promise::Promise;
-use crate::script_runtime::JSContext;
+use crate::script_runtime::{CanGc, JSContext};
 use crate::task::TaskOnce;
 use dom_struct::dom_struct;
 use ipc_channel::ipc::{self, IpcSender};
@@ -278,6 +278,7 @@ pub fn response_async<T: AsyncBluetoothListener + DomObject + 'static>(
 }
 
 // https://webbluetoothcg.github.io/web-bluetooth/#getgattchildren
+#[allow(clippy::too_many_arguments)]
 pub fn get_gatt_children<T, F>(
     attribute: &T,
     single: bool,
@@ -286,13 +287,14 @@ pub fn get_gatt_children<T, F>(
     instance_id: String,
     connected: bool,
     child_type: GATTType,
+    can_gc: CanGc,
 ) -> Rc<Promise>
 where
     T: AsyncBluetoothListener + DomObject + 'static,
     F: FnOnce(StringOrUnsignedLong) -> Fallible<UUID>,
 {
     let in_realm_proof = AlreadyInRealm::assert();
-    let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+    let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
 
     let result_uuid = if let Some(u) = uuid {
         // Step 1.
@@ -531,8 +533,13 @@ impl From<BluetoothError> for Error {
 
 impl BluetoothMethods for Bluetooth {
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetooth-requestdevice
-    fn RequestDevice(&self, option: &RequestDeviceOptions, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn RequestDevice(
+        &self,
+        option: &RequestDeviceOptions,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         // Step 1.
         if (option.filters.is_some() && option.acceptAllDevices) ||
             (option.filters.is_none() && !option.acceptAllDevices)
@@ -549,8 +556,8 @@ impl BluetoothMethods for Bluetooth {
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetooth-getavailability
-    fn GetAvailability(&self, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn GetAvailability(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         // Step 1. We did not override the method
         // Step 2 - 3. in handle_response
         let sender = response_async(&p, self);
diff --git a/components/script/dom/bluetoothdevice.rs b/components/script/dom/bluetoothdevice.rs
index a5da5f76ebc..6a74dcbb6a0 100644
--- a/components/script/dom/bluetoothdevice.rs
+++ b/components/script/dom/bluetoothdevice.rs
@@ -32,6 +32,7 @@ use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::realms::InRealm;
+use crate::script_runtime::CanGc;
 
 #[crown::unrooted_must_root_lint::must_root]
 #[derive(JSTraceable, MallocSizeOf)]
@@ -280,8 +281,8 @@ impl BluetoothDeviceMethods for BluetoothDevice {
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothdevice-watchadvertisements
-    fn WatchAdvertisements(&self, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn WatchAdvertisements(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&p, self);
         // TODO: Step 1.
         // Note: Steps 2 - 3 are implemented in components/bluetooth/lib.rs in watch_advertisements function
diff --git a/components/script/dom/bluetoothremotegattcharacteristic.rs b/components/script/dom/bluetoothremotegattcharacteristic.rs
index 29ea453e68f..d8fbc3440a9 100644
--- a/components/script/dom/bluetoothremotegattcharacteristic.rs
+++ b/components/script/dom/bluetoothremotegattcharacteristic.rs
@@ -30,6 +30,7 @@ use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::realms::InRealm;
+use crate::script_runtime::CanGc;
 
 // Maximum length of an attribute value.
 // https://www.bluetooth.org/DocMan/handlers/DownloadDoc.ashx?doc_id=286439 (Vol. 3, page 2169)
@@ -107,7 +108,7 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattcharacteristic-getdescriptor
-    fn GetDescriptor(&self, descriptor: BluetoothDescriptorUUID) -> Rc<Promise> {
+    fn GetDescriptor(&self, descriptor: BluetoothDescriptorUUID, can_gc: CanGc) -> Rc<Promise> {
         get_gatt_children(
             self,
             true,
@@ -116,11 +117,16 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
             self.get_instance_id(),
             self.Service().Device().get_gatt().Connected(),
             GATTType::Descriptor,
+            can_gc,
         )
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattcharacteristic-getdescriptors
-    fn GetDescriptors(&self, descriptor: Option<BluetoothDescriptorUUID>) -> Rc<Promise> {
+    fn GetDescriptors(
+        &self,
+        descriptor: Option<BluetoothDescriptorUUID>,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         get_gatt_children(
             self,
             false,
@@ -129,6 +135,7 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
             self.get_instance_id(),
             self.Service().Device().get_gatt().Connected(),
             GATTType::Descriptor,
+            can_gc,
         )
     }
 
@@ -138,8 +145,8 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattcharacteristic-readvalue
-    fn ReadValue(&self, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn ReadValue(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 1.
         if uuid_is_blocklisted(self.uuid.as_ref(), Blocklist::Reads) {
@@ -171,8 +178,13 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattcharacteristic-writevalue
-    fn WriteValue(&self, value: ArrayBufferViewOrArrayBuffer, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn WriteValue(
+        &self,
+        value: ArrayBufferViewOrArrayBuffer,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 1.
         if uuid_is_blocklisted(self.uuid.as_ref(), Blocklist::Writes) {
@@ -222,8 +234,8 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattcharacteristic-startnotifications
-    fn StartNotifications(&self, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn StartNotifications(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 1.
         if uuid_is_blocklisted(self.uuid.as_ref(), Blocklist::Reads) {
@@ -259,8 +271,8 @@ impl BluetoothRemoteGATTCharacteristicMethods for BluetoothRemoteGATTCharacteris
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattcharacteristic-stopnotifications
-    fn StopNotifications(&self, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn StopNotifications(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&p, self);
 
         // TODO: Step 3 - 4: Implement `active notification context set` for BluetoothRemoteGATTCharacteristic,
diff --git a/components/script/dom/bluetoothremotegattdescriptor.rs b/components/script/dom/bluetoothremotegattdescriptor.rs
index 1b07d2ee87a..1c7ce74b052 100644
--- a/components/script/dom/bluetoothremotegattdescriptor.rs
+++ b/components/script/dom/bluetoothremotegattdescriptor.rs
@@ -26,6 +26,7 @@ use crate::dom::bluetoothremotegattcharacteristic::{
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::realms::InRealm;
+use crate::script_runtime::CanGc;
 
 // http://webbluetoothcg.github.io/web-bluetooth/#bluetoothremotegattdescriptor
 #[dom_struct]
@@ -94,8 +95,8 @@ impl BluetoothRemoteGATTDescriptorMethods for BluetoothRemoteGATTDescriptor {
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattdescriptor-readvalue
-    fn ReadValue(&self, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn ReadValue(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 1.
         if uuid_is_blocklisted(self.uuid.as_ref(), Blocklist::Reads) {
@@ -126,8 +127,13 @@ impl BluetoothRemoteGATTDescriptorMethods for BluetoothRemoteGATTDescriptor {
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattdescriptor-writevalue
-    fn WriteValue(&self, value: ArrayBufferViewOrArrayBuffer, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn WriteValue(
+        &self,
+        value: ArrayBufferViewOrArrayBuffer,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 1.
         if uuid_is_blocklisted(self.uuid.as_ref(), Blocklist::Writes) {
diff --git a/components/script/dom/bluetoothremotegattserver.rs b/components/script/dom/bluetoothremotegattserver.rs
index 65c7d9ae20d..60ae98fd045 100644
--- a/components/script/dom/bluetoothremotegattserver.rs
+++ b/components/script/dom/bluetoothremotegattserver.rs
@@ -20,6 +20,7 @@ use crate::dom::bluetoothuuid::{BluetoothServiceUUID, BluetoothUUID};
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::realms::InRealm;
+use crate::script_runtime::CanGc;
 
 // https://webbluetoothcg.github.io/web-bluetooth/#bluetoothremotegattserver
 #[dom_struct]
@@ -70,9 +71,9 @@ impl BluetoothRemoteGATTServerMethods for BluetoothRemoteGATTServer {
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattserver-connect
     #[allow(unsafe_code)]
-    fn Connect(&self, comp: InRealm) -> Rc<Promise> {
+    fn Connect(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
         // Step 1.
-        let p = Promise::new_in_current_realm(comp);
+        let p = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&p, self);
 
         // TODO: Step 3: Check if the UA is currently using the Bluetooth system.
@@ -110,7 +111,7 @@ impl BluetoothRemoteGATTServerMethods for BluetoothRemoteGATTServer {
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattserver-getprimaryservice
-    fn GetPrimaryService(&self, service: BluetoothServiceUUID) -> Rc<Promise> {
+    fn GetPrimaryService(&self, service: BluetoothServiceUUID, can_gc: CanGc) -> Rc<Promise> {
         // Step 1 - 2.
         get_gatt_children(
             self,
@@ -120,11 +121,16 @@ impl BluetoothRemoteGATTServerMethods for BluetoothRemoteGATTServer {
             String::from(self.Device().Id()),
             self.Device().get_gatt().Connected(),
             GATTType::PrimaryService,
+            can_gc,
         )
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattserver-getprimaryservices
-    fn GetPrimaryServices(&self, service: Option<BluetoothServiceUUID>) -> Rc<Promise> {
+    fn GetPrimaryServices(
+        &self,
+        service: Option<BluetoothServiceUUID>,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         // Step 1 - 2.
         get_gatt_children(
             self,
@@ -134,6 +140,7 @@ impl BluetoothRemoteGATTServerMethods for BluetoothRemoteGATTServer {
             String::from(self.Device().Id()),
             self.Connected(),
             GATTType::PrimaryService,
+            can_gc,
         )
     }
 }
diff --git a/components/script/dom/bluetoothremotegattservice.rs b/components/script/dom/bluetoothremotegattservice.rs
index abb65d83c2a..76158826b78 100644
--- a/components/script/dom/bluetoothremotegattservice.rs
+++ b/components/script/dom/bluetoothremotegattservice.rs
@@ -19,6 +19,7 @@ use crate::dom::bluetoothuuid::{BluetoothCharacteristicUUID, BluetoothServiceUUI
 use crate::dom::eventtarget::EventTarget;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
+use crate::script_runtime::CanGc;
 
 // https://webbluetoothcg.github.io/web-bluetooth/#bluetoothremotegattservice
 #[dom_struct]
@@ -84,7 +85,11 @@ impl BluetoothRemoteGATTServiceMethods for BluetoothRemoteGATTService {
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattservice-getcharacteristic
-    fn GetCharacteristic(&self, characteristic: BluetoothCharacteristicUUID) -> Rc<Promise> {
+    fn GetCharacteristic(
+        &self,
+        characteristic: BluetoothCharacteristicUUID,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         get_gatt_children(
             self,
             true,
@@ -93,6 +98,7 @@ impl BluetoothRemoteGATTServiceMethods for BluetoothRemoteGATTService {
             self.get_instance_id(),
             self.Device().get_gatt().Connected(),
             GATTType::Characteristic,
+            can_gc,
         )
     }
 
@@ -100,6 +106,7 @@ impl BluetoothRemoteGATTServiceMethods for BluetoothRemoteGATTService {
     fn GetCharacteristics(
         &self,
         characteristic: Option<BluetoothCharacteristicUUID>,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         get_gatt_children(
             self,
@@ -109,11 +116,12 @@ impl BluetoothRemoteGATTServiceMethods for BluetoothRemoteGATTService {
             self.get_instance_id(),
             self.Device().get_gatt().Connected(),
             GATTType::Characteristic,
+            can_gc,
         )
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattservice-getincludedservice
-    fn GetIncludedService(&self, service: BluetoothServiceUUID) -> Rc<Promise> {
+    fn GetIncludedService(&self, service: BluetoothServiceUUID, can_gc: CanGc) -> Rc<Promise> {
         get_gatt_children(
             self,
             false,
@@ -122,11 +130,16 @@ impl BluetoothRemoteGATTServiceMethods for BluetoothRemoteGATTService {
             self.get_instance_id(),
             self.Device().get_gatt().Connected(),
             GATTType::IncludedService,
+            can_gc,
         )
     }
 
     // https://webbluetoothcg.github.io/web-bluetooth/#dom-bluetoothremotegattservice-getincludedservices
-    fn GetIncludedServices(&self, service: Option<BluetoothServiceUUID>) -> Rc<Promise> {
+    fn GetIncludedServices(
+        &self,
+        service: Option<BluetoothServiceUUID>,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         get_gatt_children(
             self,
             false,
@@ -135,6 +148,7 @@ impl BluetoothRemoteGATTServiceMethods for BluetoothRemoteGATTService {
             self.get_instance_id(),
             self.Device().get_gatt().Connected(),
             GATTType::IncludedService,
+            can_gc,
         )
     }
 
diff --git a/components/script/dom/customelementregistry.rs b/components/script/dom/customelementregistry.rs
index f72c5991d01..5739903492b 100644
--- a/components/script/dom/customelementregistry.rs
+++ b/components/script/dom/customelementregistry.rs
@@ -573,13 +573,13 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
 
     /// <https://html.spec.whatwg.org/multipage/#dom-customelementregistry-whendefined>
     #[allow(unsafe_code)]
-    fn WhenDefined(&self, name: DOMString, comp: InRealm) -> Rc<Promise> {
+    fn WhenDefined(&self, name: DOMString, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
         let global_scope = self.window.upcast::<GlobalScope>();
         let name = LocalName::from(&*name);
 
         // Step 1
         if !is_valid_custom_element_name(&name) {
-            let promise = Promise::new_in_current_realm(comp);
+            let promise = Promise::new_in_current_realm(comp, can_gc);
             promise.reject_native(&DOMException::new(global_scope, DOMErrorName::SyntaxError));
             return promise;
         }
@@ -592,7 +592,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
                 definition
                     .constructor
                     .to_jsval(*cx, constructor.handle_mut());
-                let promise = Promise::new_in_current_realm(comp);
+                let promise = Promise::new_in_current_realm(comp, can_gc);
                 promise.resolve_native(&constructor.get());
                 return promise;
             }
@@ -603,7 +603,7 @@ impl CustomElementRegistryMethods for CustomElementRegistry {
 
         // Steps 4, 5
         let promise = map.get(&name).cloned().unwrap_or_else(|| {
-            let promise = Promise::new_in_current_realm(comp);
+            let promise = Promise::new_in_current_realm(comp, can_gc);
             map.insert(name, promise.clone());
             promise
         });
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 189352c35ce..602298ec9c5 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -3894,10 +3894,10 @@ impl Document {
     }
 
     // https://fullscreen.spec.whatwg.org/#dom-element-requestfullscreen
-    pub fn enter_fullscreen(&self, pending: &Element) -> Rc<Promise> {
+    pub fn enter_fullscreen(&self, pending: &Element, can_gc: CanGc) -> Rc<Promise> {
         // Step 1
         let in_realm_proof = AlreadyInRealm::assert();
-        let promise = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+        let promise = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
         let mut error = false;
 
         // Step 4
@@ -3961,11 +3961,11 @@ impl Document {
     }
 
     // https://fullscreen.spec.whatwg.org/#exit-fullscreen
-    pub fn exit_fullscreen(&self) -> Rc<Promise> {
+    pub fn exit_fullscreen(&self, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
         // Step 1
         let in_realm_proof = AlreadyInRealm::assert();
-        let promise = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+        let promise = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
         // Step 2
         if self.fullscreen_element.get().is_none() {
             promise.reject_error(Error::Type(String::from("fullscreen is null")));
@@ -5557,8 +5557,8 @@ impl DocumentMethods for Document {
     }
 
     // https://fullscreen.spec.whatwg.org/#dom-document-exitfullscreen
-    fn ExitFullscreen(&self) -> Rc<Promise> {
-        self.exit_fullscreen()
+    fn ExitFullscreen(&self, can_gc: CanGc) -> Rc<Promise> {
+        self.exit_fullscreen(can_gc)
     }
 
     // check-tidy: no specs after this line
diff --git a/components/script/dom/element.rs b/components/script/dom/element.rs
index 2bb4e0b86c0..b6d5e4060e1 100644
--- a/components/script/dom/element.rs
+++ b/components/script/dom/element.rs
@@ -2954,9 +2954,9 @@ impl ElementMethods for Element {
     }
 
     // https://fullscreen.spec.whatwg.org/#dom-element-requestfullscreen
-    fn RequestFullscreen(&self) -> Rc<Promise> {
+    fn RequestFullscreen(&self, can_gc: CanGc) -> Rc<Promise> {
         let doc = document_from_node(self);
-        doc.enter_fullscreen(self)
+        doc.enter_fullscreen(self, can_gc)
     }
 
     // XXX Hidden under dom.shadowdom.enabled pref. Only exposed to be able
@@ -3557,7 +3557,7 @@ impl VirtualMethods for Element {
 
         let fullscreen = doc.GetFullscreenElement();
         if fullscreen.as_deref() == Some(self) {
-            doc.exit_fullscreen();
+            doc.exit_fullscreen(CanGc::note());
         }
         if let Some(ref value) = *self.id_attribute.borrow() {
             doc.unregister_element_id(self, value.clone());
diff --git a/components/script/dom/fakexrdevice.rs b/components/script/dom/fakexrdevice.rs
index 720fb19df33..e2d79660833 100644
--- a/components/script/dom/fakexrdevice.rs
+++ b/components/script/dom/fakexrdevice.rs
@@ -33,6 +33,7 @@ use crate::dom::bindings::root::DomRoot;
 use crate::dom::fakexrinputcontroller::{init_to_mock_buttons, FakeXRInputController};
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
+use crate::script_runtime::CanGc;
 use crate::task_source::TaskSource;
 
 #[dom_struct]
@@ -297,9 +298,9 @@ impl FakeXRDeviceMethods for FakeXRDevice {
     }
 
     /// <https://immersive-web.github.io/webxr-test-api/#dom-fakexrdevice-disconnect>
-    fn Disconnect(&self) -> Rc<Promise> {
+    fn Disconnect(&self, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
-        let p = Promise::new(&global);
+        let p = Promise::new(&global, can_gc);
         let mut trusted = Some(TrustedPromise::new(p.clone()));
         let (task_source, canceller) = global
             .as_window()
diff --git a/components/script/dom/fontfaceset.rs b/components/script/dom/fontfaceset.rs
index fa2fae410d4..0774f2b1617 100644
--- a/components/script/dom/fontfaceset.rs
+++ b/components/script/dom/fontfaceset.rs
@@ -27,7 +27,7 @@ impl FontFaceSet {
     pub fn new_inherited(global: &GlobalScope) -> Self {
         FontFaceSet {
             target: EventTarget::new_inherited(),
-            promise: Promise::new(global),
+            promise: Promise::new(global, CanGc::note()),
         }
     }
 
diff --git a/components/script/dom/gamepadhapticactuator.rs b/components/script/dom/gamepadhapticactuator.rs
index 483a6a25a07..3f7513b29ce 100644
--- a/components/script/dom/gamepadhapticactuator.rs
+++ b/components/script/dom/gamepadhapticactuator.rs
@@ -144,8 +144,9 @@ impl GamepadHapticActuatorMethods for GamepadHapticActuator {
         type_: GamepadHapticEffectType,
         params: &GamepadEffectParameters,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
-        let playing_effect_promise = Promise::new_in_current_realm(comp);
+        let playing_effect_promise = Promise::new_in_current_realm(comp, can_gc);
 
         // <https://www.w3.org/TR/gamepad/#dfn-valid-effect>
         match type_ {
@@ -258,8 +259,8 @@ impl GamepadHapticActuatorMethods for GamepadHapticActuator {
     }
 
     /// <https://www.w3.org/TR/gamepad/#dom-gamepadhapticactuator-reset>
-    fn Reset(&self, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn Reset(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         let document = self.global().as_window().Document();
         if !document.is_fully_active() {
diff --git a/components/script/dom/globalscope.rs b/components/script/dom/globalscope.rs
index 2458db4af8a..81574c8b50a 100644
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@@ -2810,9 +2810,10 @@ impl GlobalScope {
         &self,
         image: ImageBitmapSource,
         options: &ImageBitmapOptions,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let in_realm_proof = AlreadyInRealm::assert();
-        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
         if options.resizeWidth.is_some_and(|w| w == 0) {
             p.reject_error(Error::InvalidState);
             return p;
diff --git a/components/script/dom/gpu.rs b/components/script/dom/gpu.rs
index cdac3a5a2e0..753ff82b7ab 100644
--- a/components/script/dom/gpu.rs
+++ b/components/script/dom/gpu.rs
@@ -106,9 +106,14 @@ pub fn response_async<T: AsyncWGPUListener + DomObject + 'static>(
 
 impl GPUMethods for GPU {
     // https://gpuweb.github.io/gpuweb/#dom-gpu-requestadapter
-    fn RequestAdapter(&self, options: &GPURequestAdapterOptions, comp: InRealm) -> Rc<Promise> {
+    fn RequestAdapter(
+        &self,
+        options: &GPURequestAdapterOptions,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         let global = &self.global();
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&promise, self);
         let power_preference = match options.powerPreference {
             Some(GPUPowerPreference::Low_power) => PowerPreference::LowPower,
diff --git a/components/script/dom/gpuadapter.rs b/components/script/dom/gpuadapter.rs
index 9a8ad998280..9509475144a 100644
--- a/components/script/dom/gpuadapter.rs
+++ b/components/script/dom/gpuadapter.rs
@@ -108,9 +108,14 @@ impl Drop for GPUAdapter {
 
 impl GPUAdapterMethods for GPUAdapter {
     /// <https://gpuweb.github.io/gpuweb/#dom-gpuadapter-requestdevice>
-    fn RequestDevice(&self, descriptor: &GPUDeviceDescriptor, comp: InRealm) -> Rc<Promise> {
+    fn RequestDevice(
+        &self,
+        descriptor: &GPUDeviceDescriptor,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         // Step 2
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&promise, self);
         let mut required_features = wgt::Features::empty();
         for &ext in descriptor.requiredFeatures.iter() {
@@ -171,10 +176,15 @@ impl GPUAdapterMethods for GPUAdapter {
     }
 
     /// <https://gpuweb.github.io/gpuweb/#dom-gpuadapter-requestadapterinfo>
-    fn RequestAdapterInfo(&self, unmask_hints: Vec<DOMString>, comp: InRealm) -> Rc<Promise> {
+    fn RequestAdapterInfo(
+        &self,
+        unmask_hints: Vec<DOMString>,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         // XXX: Adapter info should be generated here ...
         // Step 1
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         // Step 4
         if !unmask_hints.is_empty() {
             todo!("unmaskHints on RequestAdapterInfo");
diff --git a/components/script/dom/gpubuffer.rs b/components/script/dom/gpubuffer.rs
index 3b6f8eb6fe3..7cd56c9741c 100644
--- a/components/script/dom/gpubuffer.rs
+++ b/components/script/dom/gpubuffer.rs
@@ -238,8 +238,9 @@ impl GPUBufferMethods for GPUBuffer {
         offset: GPUSize64,
         size: Option<GPUSize64>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         // Step 2
         if self.pending_map.borrow().is_some() {
             promise.reject_error(Error::Operation);
diff --git a/components/script/dom/gpudevice.rs b/components/script/dom/gpudevice.rs
index 840f6991292..51361118f8d 100644
--- a/components/script/dom/gpudevice.rs
+++ b/components/script/dom/gpudevice.rs
@@ -153,7 +153,7 @@ impl GPUDevice {
         let queue = GPUQueue::new(global, channel.clone(), queue);
         let limits = GPUSupportedLimits::new(global, limits);
         let features = GPUSupportedFeatures::Constructor(global, None, features, can_gc).unwrap();
-        let lost_promise = Promise::new(global);
+        let lost_promise = Promise::new(global, can_gc);
         let device = reflect_dom_object(
             Box::new(GPUDevice::new_inherited(
                 channel,
@@ -440,8 +440,9 @@ impl GPUDeviceMethods for GPUDevice {
         &self,
         descriptor: RootedTraceableBox<GPUShaderModuleDescriptor>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> DomRoot<GPUShaderModule> {
-        GPUShaderModule::create(self, descriptor, comp)
+        GPUShaderModule::create(self, descriptor, comp, can_gc)
     }
 
     /// <https://gpuweb.github.io/gpuweb/#dom-gpudevice-createcomputepipeline>
@@ -463,8 +464,9 @@ impl GPUDeviceMethods for GPUDevice {
         &self,
         descriptor: &GPUComputePipelineDescriptor,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&promise, self);
         GPUComputePipeline::create(self, descriptor, Some(sender));
         promise
@@ -508,9 +510,10 @@ impl GPUDeviceMethods for GPUDevice {
         &self,
         descriptor: &GPURenderPipelineDescriptor,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Fallible<Rc<Promise>> {
         let (implicit_ids, desc) = self.parse_render_pipeline(descriptor)?;
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&promise, self);
         GPURenderPipeline::create(self, implicit_ids, desc, Some(sender))?;
         Ok(promise)
@@ -540,8 +543,8 @@ impl GPUDeviceMethods for GPUDevice {
     }
 
     /// <https://gpuweb.github.io/gpuweb/#dom-gpudevice-poperrorscope>
-    fn PopErrorScope(&self, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn PopErrorScope(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let sender = response_async(&promise, self);
         if self
             .channel
diff --git a/components/script/dom/gpuqueue.rs b/components/script/dom/gpuqueue.rs
index 42510ce286b..f371743e681 100644
--- a/components/script/dom/gpuqueue.rs
+++ b/components/script/dom/gpuqueue.rs
@@ -188,9 +188,9 @@ impl GPUQueueMethods for GPUQueue {
     }
 
     /// <https://gpuweb.github.io/gpuweb/#dom-gpuqueue-onsubmittedworkdone>
-    fn OnSubmittedWorkDone(&self) -> Rc<Promise> {
+    fn OnSubmittedWorkDone(&self, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
-        let promise = Promise::new(&global);
+        let promise = Promise::new(&global, can_gc);
         let sender = response_async(&promise, self);
         if let Err(e) = self
             .channel
diff --git a/components/script/dom/gpushadermodule.rs b/components/script/dom/gpushadermodule.rs
index eb6aa9deb63..f08c91e32bb 100644
--- a/components/script/dom/gpushadermodule.rs
+++ b/components/script/dom/gpushadermodule.rs
@@ -82,9 +82,10 @@ impl GPUShaderModule {
         device: &GPUDevice,
         descriptor: RootedTraceableBox<GPUShaderModuleDescriptor>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> DomRoot<GPUShaderModule> {
         let program_id = device.global().wgpu_id_hub().create_shader_module_id();
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let shader_module = GPUShaderModule::new(
             &device.global(),
             device.channel().clone(),
diff --git a/components/script/dom/htmlimageelement.rs b/components/script/dom/htmlimageelement.rs
index 33f907d9985..859f2ec1d55 100644
--- a/components/script/dom/htmlimageelement.rs
+++ b/components/script/dom/htmlimageelement.rs
@@ -1703,9 +1703,9 @@ impl HTMLImageElementMethods for HTMLImageElement {
     }
 
     /// <https://html.spec.whatwg.org/multipage/#dom-img-decode>
-    fn Decode(&self) -> Rc<Promise> {
+    fn Decode(&self, can_gc: CanGc) -> Rc<Promise> {
         // Step 1
-        let promise = Promise::new(&self.global());
+        let promise = Promise::new(&self.global(), can_gc);
 
         // Step 2
         let task = ImageElementMicrotask::Decode {
diff --git a/components/script/dom/htmlmediaelement.rs b/components/script/dom/htmlmediaelement.rs
index 9f7f635d252..2e61809bb8d 100644
--- a/components/script/dom/htmlmediaelement.rs
+++ b/components/script/dom/htmlmediaelement.rs
@@ -2158,7 +2158,7 @@ impl HTMLMediaElementMethods for HTMLMediaElement {
 
     // https://html.spec.whatwg.org/multipage/#dom-media-play
     fn Play(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         // Step 1.
         // FIXME(nox): Reject promise if not allowed to play.
 
diff --git a/components/script/dom/htmlscriptelement.rs b/components/script/dom/htmlscriptelement.rs
index 4ad5d40c1a7..edeca5317db 100644
--- a/components/script/dom/htmlscriptelement.rs
+++ b/components/script/dom/htmlscriptelement.rs
@@ -572,7 +572,7 @@ fn fetch_a_classic_script(
 
 impl HTMLScriptElement {
     /// <https://html.spec.whatwg.org/multipage/#prepare-a-script>
-    pub fn prepare(&self) {
+    pub fn prepare(&self, can_gc: CanGc) {
         // Step 1.
         if self.already_started.get() {
             return;
@@ -784,6 +784,7 @@ impl HTMLScriptElement {
                         url.clone(),
                         Destination::Script,
                         options,
+                        can_gc,
                     );
 
                     if !asynch && was_parser_inserted {
@@ -842,6 +843,7 @@ impl HTMLScriptElement {
                         base_url.clone(),
                         self.id,
                         options,
+                        can_gc,
                     );
                 },
             }
@@ -1236,7 +1238,7 @@ impl VirtualMethods for HTMLScriptElement {
         if *attr.local_name() == local_name!("src") {
             if let AttributeMutation::Set(_) = mutation {
                 if !self.parser_inserted.get() && self.upcast::<Node>().is_connected() {
-                    self.prepare();
+                    self.prepare(CanGc::note());
                 }
             }
         }
@@ -1247,7 +1249,7 @@ impl VirtualMethods for HTMLScriptElement {
             s.children_changed(mutation);
         }
         if !self.parser_inserted.get() && self.upcast::<Node>().is_connected() {
-            self.prepare();
+            self.prepare(CanGc::note());
         }
     }
 
@@ -1259,7 +1261,7 @@ impl VirtualMethods for HTMLScriptElement {
         if context.tree_connected && !self.parser_inserted.get() {
             let script = Trusted::new(self);
             document_from_node(self).add_delayed_task(task!(ScriptDelayedInitialize: move || {
-                script.root().prepare();
+                script.root().prepare(CanGc::note());
             }));
         }
     }
diff --git a/components/script/dom/mediadevices.rs b/components/script/dom/mediadevices.rs
index 4207542d8c7..985f0ee9409 100644
--- a/components/script/dom/mediadevices.rs
+++ b/components/script/dom/mediadevices.rs
@@ -53,7 +53,7 @@ impl MediaDevicesMethods for MediaDevices {
         comp: InRealm,
         can_gc: CanGc,
     ) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+        let p = Promise::new_in_current_realm(comp, can_gc);
         let media = ServoMedia::get().unwrap();
         let stream = MediaStream::new(&self.global(), can_gc);
         if let Some(constraints) = convert_constraints(&constraints.audio) {
@@ -74,10 +74,10 @@ impl MediaDevicesMethods for MediaDevices {
     }
 
     /// <https://w3c.github.io/mediacapture-main/#dom-mediadevices-enumeratedevices>
-    fn EnumerateDevices(&self) -> Rc<Promise> {
+    fn EnumerateDevices(&self, can_gc: CanGc) -> Rc<Promise> {
         // Step 1.
         let in_realm_proof = AlreadyInRealm::assert();
-        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof));
+        let p = Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc);
 
         // Step 2.
         // XXX These steps should be run in parallel.
diff --git a/components/script/dom/navigationpreloadmanager.rs b/components/script/dom/navigationpreloadmanager.rs
index 88e0bcc779e..b285e1a5681 100644
--- a/components/script/dom/navigationpreloadmanager.rs
+++ b/components/script/dom/navigationpreloadmanager.rs
@@ -18,6 +18,7 @@ use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
 use crate::dom::serviceworkerregistration::ServiceWorkerRegistration;
 use crate::realms::InRealm;
+use crate::script_runtime::CanGc;
 
 #[dom_struct]
 pub struct NavigationPreloadManager {
@@ -45,8 +46,8 @@ impl NavigationPreloadManager {
 
 impl NavigationPreloadManagerMethods for NavigationPreloadManager {
     // https://w3c.github.io/ServiceWorker/#navigation-preload-manager-enable
-    fn Enable(&self, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn Enable(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // 2.
         if self.serviceworker_registration.is_active() {
@@ -67,8 +68,8 @@ impl NavigationPreloadManagerMethods for NavigationPreloadManager {
     }
 
     // https://w3c.github.io/ServiceWorker/#navigation-preload-manager-disable
-    fn Disable(&self, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn Disable(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // 2.
         if self.serviceworker_registration.is_active() {
@@ -89,8 +90,8 @@ impl NavigationPreloadManagerMethods for NavigationPreloadManager {
     }
 
     // https://w3c.github.io/ServiceWorker/#navigation-preload-manager-setheadervalue
-    fn SetHeaderValue(&self, value: ByteString, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn SetHeaderValue(&self, value: ByteString, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // 2.
         if self.serviceworker_registration.is_active() {
@@ -111,8 +112,8 @@ impl NavigationPreloadManagerMethods for NavigationPreloadManager {
     }
 
     // https://w3c.github.io/ServiceWorker/#navigation-preload-manager-getstate
-    fn GetState(&self, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn GetState(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         // 2.
         let mut state = NavigationPreloadState::empty();
 
diff --git a/components/script/dom/offlineaudiocontext.rs b/components/script/dom/offlineaudiocontext.rs
index bbc59a7801f..a994e107dfc 100644
--- a/components/script/dom/offlineaudiocontext.rs
+++ b/components/script/dom/offlineaudiocontext.rs
@@ -144,8 +144,8 @@ impl OfflineAudioContextMethods for OfflineAudioContext {
     }
 
     // https://webaudio.github.io/web-audio-api/#dom-offlineaudiocontext-startrendering
-    fn StartRendering(&self, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn StartRendering(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         if self.rendering_started.get() {
             promise.reject_error(Error::InvalidState);
             return promise;
diff --git a/components/script/dom/permissions.rs b/components/script/dom/permissions.rs
index 48d07eebcb3..558241993c2 100644
--- a/components/script/dom/permissions.rs
+++ b/components/script/dom/permissions.rs
@@ -25,7 +25,7 @@ use crate::dom::globalscope::GlobalScope;
 use crate::dom::permissionstatus::PermissionStatus;
 use crate::dom::promise::Promise;
 use crate::realms::{AlreadyInRealm, InRealm};
-use crate::script_runtime::JSContext;
+use crate::script_runtime::{CanGc, JSContext};
 
 pub trait PermissionAlgorithm {
     type Descriptor;
@@ -82,13 +82,14 @@ impl Permissions {
         cx: JSContext,
         permissionDesc: *mut JSObject,
         promise: Option<Rc<Promise>>,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         // (Query, Request) Step 3.
         let p = match promise {
             Some(promise) => promise,
             None => {
                 let in_realm_proof = AlreadyInRealm::assert();
-                Promise::new_in_current_realm(InRealm::Already(&in_realm_proof))
+                Promise::new_in_current_realm(InRealm::Already(&in_realm_proof), can_gc)
             },
         };
 
@@ -177,7 +178,9 @@ impl Permissions {
         };
         match op {
             // (Revoke) Step 5.
-            Operation::Revoke => self.manipulate(Operation::Query, cx, permissionDesc, Some(p)),
+            Operation::Revoke => {
+                self.manipulate(Operation::Query, cx, permissionDesc, Some(p), can_gc)
+            },
 
             // (Query, Request) Step 4.
             _ => p,
@@ -188,18 +191,18 @@ impl Permissions {
 #[allow(non_snake_case)]
 impl PermissionsMethods for Permissions {
     // https://w3c.github.io/permissions/#dom-permissions-query
-    fn Query(&self, cx: JSContext, permissionDesc: *mut JSObject) -> Rc<Promise> {
-        self.manipulate(Operation::Query, cx, permissionDesc, None)
+    fn Query(&self, cx: JSContext, permissionDesc: *mut JSObject, can_gc: CanGc) -> Rc<Promise> {
+        self.manipulate(Operation::Query, cx, permissionDesc, None, can_gc)
     }
 
     // https://w3c.github.io/permissions/#dom-permissions-request
-    fn Request(&self, cx: JSContext, permissionDesc: *mut JSObject) -> Rc<Promise> {
-        self.manipulate(Operation::Request, cx, permissionDesc, None)
+    fn Request(&self, cx: JSContext, permissionDesc: *mut JSObject, can_gc: CanGc) -> Rc<Promise> {
+        self.manipulate(Operation::Request, cx, permissionDesc, None, can_gc)
     }
 
     // https://w3c.github.io/permissions/#dom-permissions-revoke
-    fn Revoke(&self, cx: JSContext, permissionDesc: *mut JSObject) -> Rc<Promise> {
-        self.manipulate(Operation::Revoke, cx, permissionDesc, None)
+    fn Revoke(&self, cx: JSContext, permissionDesc: *mut JSObject, can_gc: CanGc) -> Rc<Promise> {
+        self.manipulate(Operation::Revoke, cx, permissionDesc, None, can_gc)
     }
 }
 
diff --git a/components/script/dom/promise.rs b/components/script/dom/promise.rs
index 75b117098d1..6e1a8fdfb63 100644
--- a/components/script/dom/promise.rs
+++ b/components/script/dom/promise.rs
@@ -86,16 +86,16 @@ impl Drop for Promise {
 }
 
 impl Promise {
-    pub fn new(global: &GlobalScope) -> Rc<Promise> {
+    pub fn new(global: &GlobalScope, can_gc: CanGc) -> Rc<Promise> {
         let realm = enter_realm(global);
         let comp = InRealm::Entered(&realm);
-        Promise::new_in_current_realm(comp)
+        Promise::new_in_current_realm(comp, can_gc)
     }
 
-    pub fn new_in_current_realm(_comp: InRealm) -> Rc<Promise> {
+    pub fn new_in_current_realm(_comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
         let cx = GlobalScope::get_cx();
         rooted!(in(*cx) let mut obj = ptr::null_mut::<JSObject>());
-        Promise::create_js_promise(cx, obj.handle_mut());
+        Promise::create_js_promise(cx, obj.handle_mut(), can_gc);
         Promise::new_with_js_promise(obj.handle(), cx)
     }
 
@@ -121,7 +121,9 @@ impl Promise {
     }
 
     #[allow(unsafe_code)]
-    fn create_js_promise(cx: SafeJSContext, mut obj: MutableHandleObject) {
+    // The apparently-unused CanGc parameter reflects the fact that the JS API calls
+    // like JS_NewFunction can trigger a GC.
+    fn create_js_promise(cx: SafeJSContext, mut obj: MutableHandleObject, _can_gc: CanGc) {
         unsafe {
             let do_nothing_func = JS_NewFunction(
                 *cx,
@@ -253,18 +255,25 @@ impl Promise {
     }
 
     #[allow(unsafe_code)]
-    pub fn append_native_handler(&self, handler: &PromiseNativeHandler, _comp: InRealm) {
+    pub fn append_native_handler(
+        &self,
+        handler: &PromiseNativeHandler,
+        _comp: InRealm,
+        can_gc: CanGc,
+    ) {
         let _ais = AutoEntryScript::new(&handler.global());
         let cx = GlobalScope::get_cx();
         rooted!(in(*cx) let resolve_func =
                 create_native_handler_function(*cx,
                                                handler.reflector().get_jsobject(),
-                                               NativeHandlerTask::Resolve));
+                                               NativeHandlerTask::Resolve,
+                                               can_gc));
 
         rooted!(in(*cx) let reject_func =
                 create_native_handler_function(*cx,
                                                handler.reflector().get_jsobject(),
-                                               NativeHandlerTask::Reject));
+                                               NativeHandlerTask::Reject,
+                                               can_gc));
 
         unsafe {
             let ok = AddPromiseReactions(
@@ -335,10 +344,13 @@ unsafe extern "C" fn native_handler_callback(
 }
 
 #[allow(unsafe_code)]
+// The apparently-unused CanGc argument reflects the fact that the JS API calls
+// like NewFunctionWithReserved can trigger a GC.
 fn create_native_handler_function(
     cx: *mut JSContext,
     holder: HandleObject,
     task: NativeHandlerTask,
+    _can_gc: CanGc,
 ) -> *mut JSObject {
     unsafe {
         let func = NewFunctionWithReserved(cx, Some(native_handler_callback), 1, 0, ptr::null());
diff --git a/components/script/dom/rtcpeerconnection.rs b/components/script/dom/rtcpeerconnection.rs
index 68d9592a017..cc9ce9c27f8 100644
--- a/components/script/dom/rtcpeerconnection.rs
+++ b/components/script/dom/rtcpeerconnection.rs
@@ -583,8 +583,13 @@ impl RTCPeerConnectionMethods for RTCPeerConnection {
     event_handler!(datachannel, GetOndatachannel, SetOndatachannel);
 
     /// <https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-addicecandidate>
-    fn AddIceCandidate(&self, candidate: &RTCIceCandidateInit, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn AddIceCandidate(
+        &self,
+        candidate: &RTCIceCandidateInit,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         if candidate.sdpMid.is_none() && candidate.sdpMLineIndex.is_none() {
             p.reject_error(Error::Type(
                 "one of sdpMid and sdpMLineIndex must be set".to_string(),
@@ -618,8 +623,8 @@ impl RTCPeerConnectionMethods for RTCPeerConnection {
     }
 
     /// <https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer>
-    fn CreateOffer(&self, _options: &RTCOfferOptions, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn CreateOffer(&self, _options: &RTCOfferOptions, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         if self.closed.get() {
             p.reject_error(Error::InvalidState);
             return p;
@@ -630,8 +635,13 @@ impl RTCPeerConnectionMethods for RTCPeerConnection {
     }
 
     /// <https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-createoffer>
-    fn CreateAnswer(&self, _options: &RTCAnswerOptions, comp: InRealm) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+    fn CreateAnswer(
+        &self,
+        _options: &RTCAnswerOptions,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
+        let p = Promise::new_in_current_realm(comp, can_gc);
         if self.closed.get() {
             p.reject_error(Error::InvalidState);
             return p;
@@ -652,9 +662,14 @@ impl RTCPeerConnectionMethods for RTCPeerConnection {
     }
 
     /// <https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-setlocaldescription>
-    fn SetLocalDescription(&self, desc: &RTCSessionDescriptionInit, comp: InRealm) -> Rc<Promise> {
+    fn SetLocalDescription(
+        &self,
+        desc: &RTCSessionDescriptionInit,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         // XXXManishearth validate the current state
-        let p = Promise::new_in_current_realm(comp);
+        let p = Promise::new_in_current_realm(comp, can_gc);
         let this = Trusted::new(self);
         let desc: SessionDescription = desc.into();
         let trusted_promise = TrustedPromise::new(p.clone());
@@ -693,9 +708,14 @@ impl RTCPeerConnectionMethods for RTCPeerConnection {
     }
 
     /// <https://w3c.github.io/webrtc-pc/#dom-rtcpeerconnection-setremotedescription>
-    fn SetRemoteDescription(&self, desc: &RTCSessionDescriptionInit, comp: InRealm) -> Rc<Promise> {
+    fn SetRemoteDescription(
+        &self,
+        desc: &RTCSessionDescriptionInit,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         // XXXManishearth validate the current state
-        let p = Promise::new_in_current_realm(comp);
+        let p = Promise::new_in_current_realm(comp, can_gc);
         let this = Trusted::new(self);
         let desc: SessionDescription = desc.into();
         let trusted_promise = TrustedPromise::new(p.clone());
diff --git a/components/script/dom/rtcrtpsender.rs b/components/script/dom/rtcrtpsender.rs
index 0526ec06303..08dba4ed884 100644
--- a/components/script/dom/rtcrtpsender.rs
+++ b/components/script/dom/rtcrtpsender.rs
@@ -14,6 +14,7 @@ use crate::dom::bindings::root::DomRoot;
 use crate::dom::bindings::str::DOMString;
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
+use crate::script_runtime::CanGc;
 
 #[dom_struct]
 pub struct RTCRtpSender {
@@ -50,8 +51,8 @@ impl RTCRtpSenderMethods for RTCRtpSender {
     }
 
     // https://w3c.github.io/webrtc-pc/#dom-rtcrtpsender-setparameters
-    fn SetParameters(&self, _parameters: &RTCRtpSendParameters) -> Rc<Promise> {
-        let promise = Promise::new(&self.global());
+    fn SetParameters(&self, _parameters: &RTCRtpSendParameters, can_gc: CanGc) -> Rc<Promise> {
+        let promise = Promise::new(&self.global(), can_gc);
         promise.resolve_native(&());
         promise
     }
diff --git a/components/script/dom/serviceworkercontainer.rs b/components/script/dom/serviceworkercontainer.rs
index e582fcd91e0..35121fba3a8 100644
--- a/components/script/dom/serviceworkercontainer.rs
+++ b/components/script/dom/serviceworkercontainer.rs
@@ -25,6 +25,7 @@ use crate::dom::promise::Promise;
 use crate::dom::serviceworker::ServiceWorker;
 use crate::dom::serviceworkerregistration::ServiceWorkerRegistration;
 use crate::realms::{enter_realm, InRealm};
+use crate::script_runtime::CanGc;
 use crate::task::TaskCanceller;
 use crate::task_source::dom_manipulation::DOMManipulationTaskSource;
 use crate::task_source::{TaskSource, TaskSourceName};
@@ -66,12 +67,13 @@ impl ServiceWorkerContainerMethods for ServiceWorkerContainer {
         script_url: USVString,
         options: &RegistrationOptions,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         // A: Step 2.
         let global = self.client.global();
 
         // A: Step 1
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let USVString(ref script_url) = script_url;
 
         // A: Step 3
diff --git a/components/script/dom/servoparser/mod.rs b/components/script/dom/servoparser/mod.rs
index 17fddca3b87..b29eeef3654 100644
--- a/components/script/dom/servoparser/mod.rs
+++ b/components/script/dom/servoparser/mod.rs
@@ -610,7 +610,7 @@ impl ServoParser {
             let script_nesting_level = self.script_nesting_level.get();
 
             self.script_nesting_level.set(script_nesting_level + 1);
-            script.prepare();
+            script.prepare(can_gc);
             self.script_nesting_level.set(script_nesting_level);
 
             if self.document.has_pending_parsing_blocking_script() {
diff --git a/components/script/dom/subtlecrypto.rs b/components/script/dom/subtlecrypto.rs
index 6f2bef75990..4f125f2e925 100644
--- a/components/script/dom/subtlecrypto.rs
+++ b/components/script/dom/subtlecrypto.rs
@@ -43,7 +43,7 @@ use crate::dom::promise::Promise;
 use crate::dom::window::Window;
 use crate::dom::workerglobalscope::WorkerGlobalScope;
 use crate::realms::InRealm;
-use crate::script_runtime::JSContext;
+use crate::script_runtime::{CanGc, JSContext};
 use crate::task::TaskCanceller;
 use crate::task_source::dom_manipulation::DOMManipulationTaskSource;
 use crate::task_source::TaskSource;
@@ -141,9 +141,10 @@ impl SubtleCryptoMethods for SubtleCrypto {
         key: &CryptoKey,
         data: ArrayBufferViewOrArrayBuffer,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let normalized_algorithm = normalize_algorithm(cx, algorithm, "encrypt");
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let data = match data {
             ArrayBufferViewOrArrayBuffer::ArrayBufferView(view) => view.to_vec(),
             ArrayBufferViewOrArrayBuffer::ArrayBuffer(buffer) => buffer.to_vec(),
@@ -197,9 +198,10 @@ impl SubtleCryptoMethods for SubtleCrypto {
         key: &CryptoKey,
         data: ArrayBufferViewOrArrayBuffer,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let normalized_algorithm = normalize_algorithm(cx, algorithm, "decrypt");
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         let data = match data {
             ArrayBufferViewOrArrayBuffer::ArrayBufferView(view) => view.to_vec(),
             ArrayBufferViewOrArrayBuffer::ArrayBuffer(buffer) => buffer.to_vec(),
@@ -253,9 +255,10 @@ impl SubtleCryptoMethods for SubtleCrypto {
         extractable: bool,
         key_usages: Vec<KeyUsage>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let normalized_algorithm = normalize_algorithm(cx, algorithm, "generateKey");
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         if let Err(e) = normalized_algorithm {
             promise.reject_error(e);
             return promise;
@@ -296,9 +299,10 @@ impl SubtleCryptoMethods for SubtleCrypto {
         extractable: bool,
         key_usages: Vec<KeyUsage>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let normalized_algorithm = normalize_algorithm(cx, algorithm, "importKey");
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
         if let Err(e) = normalized_algorithm {
             promise.reject_error(e);
             return promise;
@@ -360,8 +364,14 @@ impl SubtleCryptoMethods for SubtleCrypto {
     }
 
     /// <https://w3c.github.io/webcrypto/#SubtleCrypto-method-exportKey>
-    fn ExportKey(&self, format: KeyFormat, key: &CryptoKey, comp: InRealm) -> Rc<Promise> {
-        let promise = Promise::new_in_current_realm(comp);
+    fn ExportKey(
+        &self,
+        format: KeyFormat,
+        key: &CryptoKey,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         let (task_source, canceller) = self.task_source_with_canceller();
         let this = Trusted::new(self);
diff --git a/components/script/dom/testbinding.rs b/components/script/dom/testbinding.rs
index 402a76687e4..2c91ce7fac5 100644
--- a/components/script/dom/testbinding.rs
+++ b/components/script/dom/testbinding.rs
@@ -1013,6 +1013,7 @@ impl TestBindingMethods for TestBinding {
         resolve: Option<Rc<SimpleCallback>>,
         reject: Option<Rc<SimpleCallback>>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let global = self.global();
         let handler = PromiseNativeHandler::new(
@@ -1020,8 +1021,8 @@ impl TestBindingMethods for TestBinding {
             resolve.map(SimpleHandler::new_boxed),
             reject.map(SimpleHandler::new_boxed),
         );
-        let p = Promise::new_in_current_realm(comp);
-        p.append_native_handler(&handler, comp);
+        let p = Promise::new_in_current_realm(comp, can_gc);
+        p.append_native_handler(&handler, comp, can_gc);
         return p;
 
         #[derive(JSTraceable, MallocSizeOf)]
@@ -1042,8 +1043,8 @@ impl TestBindingMethods for TestBinding {
         }
     }
 
-    fn PromiseAttribute(&self, comp: InRealm) -> Rc<Promise> {
-        Promise::new_in_current_realm(comp)
+    fn PromiseAttribute(&self, comp: InRealm, can_gc: CanGc) -> Rc<Promise> {
+        Promise::new_in_current_realm(comp, can_gc)
     }
 
     fn AcceptPromise(&self, _promise: &Promise) {}
diff --git a/components/script/dom/testworklet.rs b/components/script/dom/testworklet.rs
index 97d016d41ac..9f3fa667590 100644
--- a/components/script/dom/testworklet.rs
+++ b/components/script/dom/testworklet.rs
@@ -63,8 +63,9 @@ impl TestWorkletMethods for TestWorklet {
         moduleURL: USVString,
         options: &WorkletOptions,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
-        self.worklet.AddModule(moduleURL, options, comp)
+        self.worklet.AddModule(moduleURL, options, comp, can_gc)
     }
 
     fn Lookup(&self, key: DOMString) -> Option<DOMString> {
diff --git a/components/script/dom/webgl2renderingcontext.rs b/components/script/dom/webgl2renderingcontext.rs
index 2fdc56611d7..038f00df9df 100644
--- a/components/script/dom/webgl2renderingcontext.rs
+++ b/components/script/dom/webgl2renderingcontext.rs
@@ -4479,9 +4479,9 @@ impl WebGL2RenderingContextMethods for WebGL2RenderingContext {
     }
 
     /// <https://immersive-web.github.io/webxr/#dom-webglrenderingcontextbase-makexrcompatible>
-    fn MakeXRCompatible(&self) -> Rc<Promise> {
+    fn MakeXRCompatible(&self, can_gc: CanGc) -> Rc<Promise> {
         // XXXManishearth Fill in with compatibility checks when rust-webxr supports this
-        let p = Promise::new(&self.global());
+        let p = Promise::new(&self.global(), can_gc);
         p.resolve_native(&());
         p
     }
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index 5c213c3eee2..39b9461f66b 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -4688,9 +4688,9 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     /// <https://immersive-web.github.io/webxr/#dom-webglrenderingcontextbase-makexrcompatible>
-    fn MakeXRCompatible(&self) -> Rc<Promise> {
+    fn MakeXRCompatible(&self, can_gc: CanGc) -> Rc<Promise> {
         // XXXManishearth Fill in with compatibility checks when rust-webxr supports this
-        let p = Promise::new(&self.global());
+        let p = Promise::new(&self.global(), can_gc);
         p.resolve_native(&());
         p
     }
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index b0475a8a6df..60bdb11d223 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -932,10 +932,11 @@ impl WindowMethods for Window {
         &self,
         image: ImageBitmapSource,
         options: &ImageBitmapOptions,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let p = self
             .upcast::<GlobalScope>()
-            .create_image_bitmap(image, options);
+            .create_image_bitmap(image, options, can_gc);
         p
     }
 
diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index 76464580563..47bd9232e2d 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -389,10 +389,11 @@ impl WorkerGlobalScopeMethods for WorkerGlobalScope {
         &self,
         image: ImageBitmapSource,
         options: &ImageBitmapOptions,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let p = self
             .upcast::<GlobalScope>()
-            .create_image_bitmap(image, options);
+            .create_image_bitmap(image, options, can_gc);
         p
     }
 
diff --git a/components/script/dom/worklet.rs b/components/script/dom/worklet.rs
index a796bb98071..5f639d3214e 100644
--- a/components/script/dom/worklet.rs
+++ b/components/script/dom/worklet.rs
@@ -49,7 +49,7 @@ use crate::dom::workletglobalscope::{
 };
 use crate::fetch::load_whole_resource;
 use crate::realms::InRealm;
-use crate::script_runtime::{CommonScriptMsg, Runtime, ScriptThreadEventCategory};
+use crate::script_runtime::{CanGc, CommonScriptMsg, Runtime, ScriptThreadEventCategory};
 use crate::script_thread::{MainThreadScriptMsg, ScriptThread};
 use crate::task::TaskBox;
 use crate::task_source::TaskSourceName;
@@ -123,9 +123,10 @@ impl WorkletMethods for Worklet {
         module_url: USVString,
         options: &WorkletOptions,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         // Step 1.
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         // Step 3.
         let module_url_record = match self.window.Document().base_url().join(&module_url.0) {
diff --git a/components/script/dom/xrsession.rs b/components/script/dom/xrsession.rs
index 47397dd174e..3fb0a14fe13 100644
--- a/components/script/dom/xrsession.rs
+++ b/components/script/dom/xrsession.rs
@@ -831,7 +831,7 @@ impl XRSessionMethods for XRSession {
         comp: InRealm,
         can_gc: CanGc,
     ) -> Rc<Promise> {
-        let p = Promise::new_in_current_realm(comp);
+        let p = Promise::new_in_current_realm(comp, can_gc);
 
         // https://immersive-web.github.io/webxr/#create-a-reference-space
 
@@ -892,7 +892,7 @@ impl XRSessionMethods for XRSession {
     /// <https://immersive-web.github.io/webxr/#dom-xrsession-end>
     fn End(&self, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
-        let p = Promise::new(&global);
+        let p = Promise::new(&global, can_gc);
         if self.ended.get() && self.end_promises.borrow().is_empty() {
             // If the session has completely ended and all end promises have been resolved,
             // don't queue up more end promises
@@ -922,8 +922,8 @@ impl XRSessionMethods for XRSession {
     }
 
     // https://immersive-web.github.io/hit-test/#dom-xrsession-requesthittestsource
-    fn RequestHitTestSource(&self, options: &XRHitTestOptionsInit) -> Rc<Promise> {
-        let p = Promise::new(&self.global());
+    fn RequestHitTestSource(&self, options: &XRHitTestOptionsInit, can_gc: CanGc) -> Rc<Promise> {
+        let p = Promise::new(&self.global(), can_gc);
 
         if !self
             .session
@@ -1025,10 +1025,15 @@ impl XRSessionMethods for XRSession {
     }
 
     /// <https://www.w3.org/TR/webxr/#dom-xrsession-updatetargetframerate>
-    fn UpdateTargetFrameRate(&self, rate: Finite<f32>, comp: InRealm) -> Rc<Promise> {
+    fn UpdateTargetFrameRate(
+        &self,
+        rate: Finite<f32>,
+        comp: InRealm,
+        can_gc: CanGc,
+    ) -> Rc<Promise> {
         let mut session = self.session.borrow_mut();
         let supported_frame_rates = session.supported_frame_rates();
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         if self.mode == XRSessionMode::Inline ||
             supported_frame_rates.is_empty() ||
diff --git a/components/script/dom/xrsystem.rs b/components/script/dom/xrsystem.rs
index 6b88fa2cc8e..e07a8f4a50e 100644
--- a/components/script/dom/xrsystem.rs
+++ b/components/script/dom/xrsystem.rs
@@ -32,6 +32,7 @@ use crate::dom::window::Window;
 use crate::dom::xrsession::XRSession;
 use crate::dom::xrtest::XRTest;
 use crate::realms::InRealm;
+use crate::script_runtime::CanGc;
 use crate::script_thread::ScriptThread;
 use crate::task_source::TaskSource;
 
@@ -111,9 +112,9 @@ impl From<XRSessionMode> for SessionMode {
 
 impl XRSystemMethods for XRSystem {
     /// <https://immersive-web.github.io/webxr/#dom-xr-issessionsupported>
-    fn IsSessionSupported(&self, mode: XRSessionMode) -> Rc<Promise> {
+    fn IsSessionSupported(&self, mode: XRSessionMode, can_gc: CanGc) -> Rc<Promise> {
         // XXXManishearth this should select an XR device first
-        let promise = Promise::new(&self.global());
+        let promise = Promise::new(&self.global(), can_gc);
         let mut trusted = Some(TrustedPromise::new(promise.clone()));
         let global = self.global();
         let window = global.as_window();
@@ -160,10 +161,11 @@ impl XRSystemMethods for XRSystem {
         mode: XRSessionMode,
         init: RootedTraceableBox<XRSessionInit>,
         comp: InRealm,
+        can_gc: CanGc,
     ) -> Rc<Promise> {
         let global = self.global();
         let window = global.as_window();
-        let promise = Promise::new_in_current_realm(comp);
+        let promise = Promise::new_in_current_realm(comp, can_gc);
 
         if mode != XRSessionMode::Inline {
             if !ScriptThread::is_user_interacting() {
diff --git a/components/script/dom/xrtest.rs b/components/script/dom/xrtest.rs
index bd0a8b2206a..b50549d8be2 100644
--- a/components/script/dom/xrtest.rs
+++ b/components/script/dom/xrtest.rs
@@ -25,6 +25,7 @@ use crate::dom::bindings::root::{Dom, DomRoot};
 use crate::dom::fakexrdevice::{get_origin, get_views, get_world, FakeXRDevice};
 use crate::dom::globalscope::GlobalScope;
 use crate::dom::promise::Promise;
+use crate::script_runtime::CanGc;
 use crate::script_thread::ScriptThread;
 use crate::task_source::TaskSource;
 
@@ -67,9 +68,9 @@ impl XRTest {
 impl XRTestMethods for XRTest {
     /// <https://github.com/immersive-web/webxr-test-api/blob/master/explainer.md>
     #[allow(unsafe_code)]
-    fn SimulateDeviceConnection(&self, init: &FakeXRDeviceInit) -> Rc<Promise> {
+    fn SimulateDeviceConnection(&self, init: &FakeXRDeviceInit, can_gc: CanGc) -> Rc<Promise> {
         let global = self.global();
-        let p = Promise::new(&global);
+        let p = Promise::new(&global, can_gc);
 
         let origin = if let Some(ref o) = init.viewerOrigin {
             match get_origin(o) {
@@ -188,10 +189,10 @@ impl XRTestMethods for XRTest {
     }
 
     /// <https://github.com/immersive-web/webxr-test-api/blob/master/explainer.md>
-    fn DisconnectAllDevices(&self) -> Rc<Promise> {
+    fn DisconnectAllDevices(&self, can_gc: CanGc) -> Rc<Promise> {
         // XXXManishearth implement device disconnection and session ending
         let global = self.global();
-        let p = Promise::new(&global);
+        let p = Promise::new(&global, can_gc);
         let mut devices = self.devices_connected.borrow_mut();
         if devices.is_empty() {
             p.resolve_native(&());