Include `WebViewId` into EmbedderMsg variants where possible (#35211)

`EmbedderMsg` was previously paired with an implicit
`Option<WebViewId>`, even though almost all variants were either always
`Some` or always `None`, depending on whether there was a `WebView
involved.

This patch adds the `WebViewId` to as many `EmbedderMsg` variants as
possible, so we can call their associated `WebView` delegate methods
without needing to check and unwrap the `Option`. In many cases, this
required more changes to plumb through the `WebViewId`.

Notably, all `Request`s now explicitly need a `WebView` or not, in order
to ensure that it is passed when appropriate.

Signed-off-by: Delan Azabani <dazabani@igalia.com>
Co-authored-by: Martin Robinson <mrobinson@igalia.com>

25 files changed, 196 insertions, 129 deletions

diff --git a/components/script/dom/bluetooth.rs b/components/script/dom/bluetooth.rs
index 42b18974b5f..9141ee17450 100644
--- a/components/script/dom/bluetooth.rs
+++ b/components/script/dom/bluetooth.rs
@@ -220,6 +220,7 @@ impl Bluetooth {
         }
 
         let option = RequestDeviceoptions::new(
+            self.global().as_window().webview_id(),
             BluetoothScanfilterSequence::new(uuid_filters),
             ServiceUUIDSequence::new(optional_services_uuids),
         );
diff --git a/components/script/dom/dedicatedworkerglobalscope.rs b/components/script/dom/dedicatedworkerglobalscope.rs
index 745b5dd9aeb..ba4ac308ad0 100644
--- a/components/script/dom/dedicatedworkerglobalscope.rs
+++ b/components/script/dom/dedicatedworkerglobalscope.rs
@@ -6,7 +6,7 @@ use std::sync::atomic::AtomicBool;
 use std::sync::Arc;
 use std::thread::{self, JoinHandle};
 
-use base::id::{BrowsingContextId, PipelineId, TopLevelBrowsingContextId};
+use base::id::{BrowsingContextId, PipelineId, TopLevelBrowsingContextId, WebViewId};
 use crossbeam_channel::{unbounded, Receiver, Sender};
 use devtools_traits::DevtoolScriptControlMsg;
 use dom_struct::dom_struct;
@@ -236,6 +236,10 @@ impl WorkerEventLoopMethods for DedicatedWorkerGlobalScope {
 }
 
 impl DedicatedWorkerGlobalScope {
+    pub(crate) fn webview_id(&self) -> Option<WebViewId> {
+        WebViewId::installed()
+    }
+
     #[allow(clippy::too_many_arguments)]
     fn new_inherited(
         init: WorkerGlobalScopeInit,
@@ -361,15 +365,19 @@ impl DedicatedWorkerGlobalScope {
 
                 let referrer = referrer_url.map(Referrer::ReferrerUrl).unwrap_or(referrer);
 
-                let request = RequestBuilder::new(worker_url.clone(), referrer)
-                    .destination(Destination::Worker)
-                    .mode(RequestMode::SameOrigin)
-                    .credentials_mode(CredentialsMode::CredentialsSameOrigin)
-                    .parser_metadata(ParserMetadata::NotParserInserted)
-                    .use_url_credentials(true)
-                    .pipeline_id(Some(pipeline_id))
-                    .referrer_policy(referrer_policy)
-                    .origin(origin);
+                let request = RequestBuilder::new(
+                    top_level_browsing_context_id,
+                    worker_url.clone(),
+                    referrer,
+                )
+                .destination(Destination::Worker)
+                .mode(RequestMode::SameOrigin)
+                .credentials_mode(CredentialsMode::CredentialsSameOrigin)
+                .parser_metadata(ParserMetadata::NotParserInserted)
+                .use_url_credentials(true)
+                .pipeline_id(Some(pipeline_id))
+                .referrer_policy(referrer_policy)
+                .origin(origin);
 
                 let runtime = unsafe {
                     let task_source = SendableTaskSource {
diff --git a/components/script/dom/document.rs b/components/script/dom/document.rs
index 689a848caed..f7bfc88de82 100644
--- a/components/script/dom/document.rs
+++ b/components/script/dom/document.rs
@@ -15,6 +15,7 @@ use std::sync::{LazyLock, Mutex};
 use std::time::{Duration, Instant};
 
 use base::cross_process_instant::CrossProcessInstant;
+use base::id::WebViewId;
 use canvas_traits::webgl::{self, WebGLContextId, WebGLMsg};
 use chrono::Local;
 use content_security_policy::{self as csp, CspList};
@@ -648,6 +649,10 @@ impl Document {
         }
     }
 
+    pub(crate) fn webview_id(&self) -> WebViewId {
+        self.window.webview_id()
+    }
+
     #[inline]
     pub(crate) fn window(&self) -> &Window {
         &self.window
@@ -1027,13 +1032,13 @@ impl Document {
         match state {
             DocumentReadyState::Loading => {
                 if self.window().is_top_level() {
-                    self.send_to_embedder(EmbedderMsg::LoadStart);
-                    self.send_to_embedder(EmbedderMsg::Status(None));
+                    self.send_to_embedder(EmbedderMsg::LoadStart(self.webview_id()));
+                    self.send_to_embedder(EmbedderMsg::Status(self.webview_id(), None));
                 }
             },
             DocumentReadyState::Complete => {
                 if self.window().is_top_level() {
-                    self.send_to_embedder(EmbedderMsg::LoadComplete);
+                    self.send_to_embedder(EmbedderMsg::LoadComplete(self.webview_id()));
                 }
                 update_with_current_instant(&self.dom_complete);
             },
@@ -1121,7 +1126,7 @@ impl Document {
 
             // Notify the embedder to hide the input method.
             if elem.input_method_type().is_some() {
-                self.send_to_embedder(EmbedderMsg::HideIME);
+                self.send_to_embedder(EmbedderMsg::HideIME(self.webview_id()));
             }
         }
 
@@ -1165,6 +1170,7 @@ impl Document {
                     (None, false)
                 };
                 self.send_to_embedder(EmbedderMsg::ShowIME(
+                    self.webview_id(),
                     kind,
                     text,
                     multiline,
@@ -1225,7 +1231,7 @@ impl Document {
         let window = self.window();
         if window.is_top_level() {
             let title = self.title().map(String::from);
-            self.send_to_embedder(EmbedderMsg::ChangePageTitle(title));
+            self.send_to_embedder(EmbedderMsg::ChangePageTitle(self.webview_id(), title));
         }
     }
 
@@ -1621,7 +1627,7 @@ impl Document {
         // Step 1
         if drag_data_store.list_len() > 0 {
             // Step 1.1 Clear the clipboard.
-            self.send_to_embedder(EmbedderMsg::ClearClipboardContents);
+            self.send_to_embedder(EmbedderMsg::ClearClipboardContents(self.webview_id()));
             // Step 1.2
             for item in drag_data_store.iter_item_list() {
                 match item {
@@ -1629,7 +1635,10 @@ impl Document {
                         // Step 1.2.1.1 Ensure encoding is correct per OS and locale conventions
                         // Step 1.2.1.2 Normalize line endings according to platform conventions
                         // Step 1.2.1.3
-                        self.send_to_embedder(EmbedderMsg::SetClipboardContents(string.data()));
+                        self.send_to_embedder(EmbedderMsg::SetClipboardContents(
+                            self.webview_id(),
+                            string.data(),
+                        ));
                     },
                     Kind::File(_) => {
                         // Step 1.2.2 If data is of a type listed in the mandatory data types list, then
@@ -1642,7 +1651,7 @@ impl Document {
             // Step 2.1
             if drag_data_store.clear_was_called {
                 // Step 2.1.1 If types-to-clear list is empty, clear the clipboard
-                self.send_to_embedder(EmbedderMsg::ClearClipboardContents);
+                self.send_to_embedder(EmbedderMsg::ClearClipboardContents(self.webview_id()));
                 // Step 2.1.2 Else remove the types in the list from the clipboard
                 // As of now this can't be done with Arboard, and it's possible that will be removed from the spec
             }
@@ -2049,7 +2058,7 @@ impl Document {
         }
 
         if cancel_state == EventDefault::Allowed {
-            let msg = EmbedderMsg::Keyboard(keyboard_event.clone());
+            let msg = EmbedderMsg::Keyboard(self.webview_id(), keyboard_event.clone());
             self.send_to_embedder(msg);
 
             // This behavior is unspecced
@@ -2455,7 +2464,7 @@ impl Document {
             .is_empty();
         if default_prevented || return_value_not_empty {
             let (chan, port) = ipc::channel().expect("Failed to create IPC channel!");
-            let msg = EmbedderMsg::AllowUnload(chan);
+            let msg = EmbedderMsg::AllowUnload(self.webview_id(), chan);
             self.send_to_embedder(msg);
             can_unload = port.recv().unwrap();
         }
@@ -4049,7 +4058,7 @@ impl Document {
         let window = self.window();
         // Step 6
         if !error {
-            let event = EmbedderMsg::SetFullscreenState(true);
+            let event = EmbedderMsg::SetFullscreenState(self.webview_id(), true);
             self.send_to_embedder(event);
         }
 
@@ -4091,7 +4100,7 @@ impl Document {
 
         let window = self.window();
         // Step 8
-        let event = EmbedderMsg::SetFullscreenState(false);
+        let event = EmbedderMsg::SetFullscreenState(self.webview_id(), false);
         self.send_to_embedder(event);
 
         // Step 9
diff --git a/components/script/dom/eventsource.rs b/components/script/dom/eventsource.rs
index 1d68817ace5..b75289497b8 100644
--- a/components/script/dom/eventsource.rs
+++ b/components/script/dom/eventsource.rs
@@ -554,6 +554,7 @@ impl EventSourceMethods<crate::DomTypeHolder> for EventSource {
         // Step 8
         // TODO: Step 9 set request's client settings
         let mut request = create_a_potential_cors_request(
+            global.webview_id(),
             url_record,
             Destination::None,
             Some(cors_attribute_state),
diff --git a/components/script/dom/gamepadhapticactuator.rs b/components/script/dom/gamepadhapticactuator.rs
index d152f633c02..cd93f3421bc 100644
--- a/components/script/dom/gamepadhapticactuator.rs
+++ b/components/script/dom/gamepadhapticactuator.rs
@@ -235,6 +235,7 @@ impl GamepadHapticActuatorMethods<crate::DomTypeHolder> for GamepadHapticActuato
             weak_magnitude: *params.weakMagnitude,
         };
         let event = EmbedderMsg::PlayGamepadHapticEffect(
+            document.webview_id(),
             self.gamepad_index as usize,
             embedder_traits::GamepadHapticEffectType::DualRumble(params),
             effect_complete_sender,
@@ -287,8 +288,11 @@ impl GamepadHapticActuatorMethods<crate::DomTypeHolder> for GamepadHapticActuato
             }),
         );
 
-        let event =
-            EmbedderMsg::StopGamepadHapticEffect(self.gamepad_index as usize, effect_stop_sender);
+        let event = EmbedderMsg::StopGamepadHapticEffect(
+            document.webview_id(),
+            self.gamepad_index as usize,
+            effect_stop_sender,
+        );
         self.global().as_window().send_to_embedder(event);
 
         self.playing_effect_promise.borrow().clone().unwrap()
@@ -356,7 +360,12 @@ impl GamepadHapticActuator {
 
         let (send, _rcv) = ipc::channel().expect("ipc channel failure");
 
-        let event = EmbedderMsg::StopGamepadHapticEffect(self.gamepad_index as usize, send);
+        let document = self.global().as_window().Document();
+        let event = EmbedderMsg::StopGamepadHapticEffect(
+            document.webview_id(),
+            self.gamepad_index as usize,
+            send,
+        );
         self.global().as_window().send_to_embedder(event);
     }
 }
diff --git a/components/script/dom/globalscope.rs b/components/script/dom/globalscope.rs
index 62d9fee32bd..2a510c25668 100644
--- a/components/script/dom/globalscope.rs
+++ b/components/script/dom/globalscope.rs
@@ -16,7 +16,7 @@ use std::{mem, ptr};
 
 use base::id::{
     BlobId, BroadcastChannelRouterId, MessagePortId, MessagePortRouterId, PipelineId,
-    ServiceWorkerId, ServiceWorkerRegistrationId,
+    ServiceWorkerId, ServiceWorkerRegistrationId, WebViewId,
 };
 use content_security_policy::{CheckResult, CspList, PolicyDisposition};
 use crossbeam_channel::Sender;
@@ -691,6 +691,20 @@ impl FileListener {
 }
 
 impl GlobalScope {
+    /// A sender to the event loop of this global scope. This either sends to the Worker event loop
+    /// or the ScriptThread event loop in the case of a `Window`. This can be `None` for dedicated
+    /// workers that are not currently handling a message.
+    pub(crate) fn webview_id(&self) -> Option<WebViewId> {
+        if let Some(window) = self.downcast::<Window>() {
+            Some(window.webview_id())
+        } else if let Some(dedicated) = self.downcast::<DedicatedWorkerGlobalScope>() {
+            dedicated.webview_id()
+        } else {
+            // ServiceWorkerGlobalScope, PaintWorklet, or DissimilarOriginWindow
+            None
+        }
+    }
+
     #[allow(clippy::too_many_arguments)]
     pub(crate) fn new_inherited(
         pipeline_id: PipelineId,
diff --git a/components/script/dom/htmlbodyelement.rs b/components/script/dom/htmlbodyelement.rs
index d3e540f562f..228e1490200 100644
--- a/components/script/dom/htmlbodyelement.rs
+++ b/components/script/dom/htmlbodyelement.rs
@@ -153,7 +153,7 @@ impl VirtualMethods for HTMLBodyElement {
         let window = self.owner_window();
         window.prevent_layout_until_load_event();
         if window.is_top_level() {
-            window.send_to_embedder(EmbedderMsg::HeadParsed);
+            window.send_to_embedder(EmbedderMsg::HeadParsed(window.webview_id()));
         }
     }
 
diff --git a/components/script/dom/htmlimageelement.rs b/components/script/dom/htmlimageelement.rs
index 36fa7b9ee67..8e563c16e54 100644
--- a/components/script/dom/htmlimageelement.rs
+++ b/components/script/dom/htmlimageelement.rs
@@ -10,7 +10,6 @@ use std::sync::Arc;
 use std::{char, mem};
 
 use app_units::{Au, AU_PER_PX};
-use base::id::PipelineId;
 use cssparser::{Parser, ParserInput};
 use dom_struct::dom_struct;
 use euclid::Point2D;
@@ -23,16 +22,14 @@ use net_traits::image_cache::{
     ImageCache, ImageCacheResult, ImageOrMetadataAvailable, ImageResponder, ImageResponse,
     PendingImageId, UsePlaceholder,
 };
-use net_traits::request::{
-    CorsSettings, Destination, Initiator, Referrer, RequestBuilder, RequestId,
-};
+use net_traits::request::{Destination, Initiator, RequestId};
 use net_traits::{
     FetchMetadata, FetchResponseListener, FetchResponseMsg, NetworkError, ReferrerPolicy,
     ResourceFetchTiming, ResourceTimingType,
 };
 use num_traits::ToPrimitive;
 use pixels::{CorsStatus, Image, ImageMetadata};
-use servo_url::origin::{ImmutableOrigin, MutableOrigin};
+use servo_url::origin::MutableOrigin;
 use servo_url::ServoUrl;
 use style::attr::{parse_integer, parse_length, AttrValue, LengthOrPercentageOrAuto};
 use style::context::QuirksMode;
@@ -318,34 +315,6 @@ impl PreInvoke for ImageContext {
     }
 }
 
-#[derive(PartialEq)]
-pub(crate) enum FromPictureOrSrcSet {
-    Yes,
-    No,
-}
-
-// https://html.spec.whatwg.org/multipage/#update-the-image-data steps 17-20
-// This function is also used to prefetch an image in `script::dom::servoparser::prefetch`.
-pub(crate) fn image_fetch_request(
-    img_url: ServoUrl,
-    origin: ImmutableOrigin,
-    referrer: Referrer,
-    pipeline_id: PipelineId,
-    cors_setting: Option<CorsSettings>,
-    referrer_policy: ReferrerPolicy,
-    from_picture_or_srcset: FromPictureOrSrcSet,
-) -> RequestBuilder {
-    let mut request =
-        create_a_potential_cors_request(img_url, Destination::Image, cors_setting, None, referrer)
-            .origin(origin)
-            .pipeline_id(Some(pipeline_id))
-            .referrer_policy(referrer_policy);
-    if from_picture_or_srcset == FromPictureOrSrcSet::Yes {
-        request = request.initiator(Initiator::ImageSet);
-    }
-    request
-}
-
 #[allow(non_snake_case)]
 impl HTMLImageElement {
     /// Update the current image with a valid URL.
@@ -445,19 +414,23 @@ impl HTMLImageElement {
             url: img_url.clone(),
         };
 
-        let request = image_fetch_request(
+        // https://html.spec.whatwg.org/multipage/#update-the-image-data steps 17-20
+        // This function is also used to prefetch an image in `script::dom::servoparser::prefetch`.
+        let mut request = create_a_potential_cors_request(
+            Some(window.webview_id()),
             img_url.clone(),
-            document.origin().immutable().clone(),
-            document.global().get_referrer(),
-            document.global().pipeline_id(),
+            Destination::Image,
             cors_setting_for_element(self.upcast()),
-            referrer_policy_for_element(self.upcast()),
-            if Self::uses_srcset_or_picture(self.upcast()) {
-                FromPictureOrSrcSet::Yes
-            } else {
-                FromPictureOrSrcSet::No
-            },
-        );
+            None,
+            document.global().get_referrer(),
+        )
+        .origin(document.origin().immutable().clone())
+        .pipeline_id(Some(document.global().pipeline_id()))
+        .referrer_policy(referrer_policy_for_element(self.upcast()));
+
+        if Self::uses_srcset_or_picture(self.upcast()) {
+            request = request.initiator(Initiator::ImageSet);
+        }
 
         // This is a background load because the load blocker already fulfills the
         // purpose of delaying the document's load event.
diff --git a/components/script/dom/htmlinputelement.rs b/components/script/dom/htmlinputelement.rs
index e8844084c68..e5c3270f27e 100644
--- a/components/script/dom/htmlinputelement.rs
+++ b/components/script/dom/htmlinputelement.rs
@@ -24,7 +24,6 @@ use net_traits::blob_url_store::get_blob_origin;
 use net_traits::filemanager_thread::FileManagerThreadMsg;
 use net_traits::{CoreResourceMsg, IpcSend};
 use profile_traits::ipc;
-use script_traits::ScriptToConstellationChan;
 use servo_atoms::Atom;
 use style::attr::AttrValue;
 use style::str::{split_commas, str_join};
@@ -34,6 +33,7 @@ use unicode_bidi::{bidi_class, BidiClass};
 use url::Url;
 
 use super::bindings::str::{FromInputValueString, ToInputValueString};
+use crate::clipboard_provider::EmbedderClipboardProvider;
 use crate::dom::activation::Activatable;
 use crate::dom::attr::Attr;
 use crate::dom::bindings::cell::DomRefCell;
@@ -299,7 +299,7 @@ pub(crate) struct HTMLInputElement {
     minlength: Cell<i32>,
     #[ignore_malloc_size_of = "TextInput contains an IPCSender which cannot be measured"]
     #[no_trace]
-    textinput: DomRefCell<TextInput<ScriptToConstellationChan>>,
+    textinput: DomRefCell<TextInput<EmbedderClipboardProvider>>,
     // https://html.spec.whatwg.org/multipage/#concept-input-value-dirty-flag
     value_dirty: Cell<bool>,
     // not specified explicitly, but implied by the fact that sanitization can't
@@ -334,7 +334,7 @@ impl HTMLInputElement {
         prefix: Option<Prefix>,
         document: &Document,
     ) -> HTMLInputElement {
-        let chan = document
+        let constellation_sender = document
             .window()
             .as_global_scope()
             .script_to_constellation_chan()
@@ -355,7 +355,10 @@ impl HTMLInputElement {
             textinput: DomRefCell::new(TextInput::new(
                 Single,
                 DOMString::new(),
-                chan,
+                EmbedderClipboardProvider {
+                    constellation_sender,
+                    webview_id: document.webview_id(),
+                },
                 None,
                 None,
                 SelectionDirection::None,
@@ -1897,6 +1900,7 @@ impl HTMLInputElement {
         let mut files: Vec<DomRoot<File>> = vec![];
         let mut error = None;
 
+        let webview_id = window.webview_id();
         let filter = filter_from_accept(&self.Accept());
         let target = self.upcast::<EventTarget>();
 
@@ -1906,7 +1910,8 @@ impl HTMLInputElement {
 
             let (chan, recv) = ipc::channel(self.global().time_profiler_chan().clone())
                 .expect("Error initializing channel");
-            let msg = FileManagerThreadMsg::SelectFiles(filter, chan, origin, opt_test_paths);
+            let msg =
+                FileManagerThreadMsg::SelectFiles(webview_id, filter, chan, origin, opt_test_paths);
             resource_threads
                 .send(CoreResourceMsg::ToFileManager(msg))
                 .unwrap();
@@ -1933,7 +1938,8 @@ impl HTMLInputElement {
 
             let (chan, recv) = ipc::channel(self.global().time_profiler_chan().clone())
                 .expect("Error initializing channel");
-            let msg = FileManagerThreadMsg::SelectFile(filter, chan, origin, opt_test_path);
+            let msg =
+                FileManagerThreadMsg::SelectFile(webview_id, filter, chan, origin, opt_test_path);
             resource_threads
                 .send(CoreResourceMsg::ToFileManager(msg))
                 .unwrap();
diff --git a/components/script/dom/htmllinkelement.rs b/components/script/dom/htmllinkelement.rs
index 50d5e274c85..299be2d2156 100644
--- a/components/script/dom/htmllinkelement.rs
+++ b/components/script/dom/htmllinkelement.rs
@@ -6,6 +6,7 @@ use std::borrow::{Borrow, ToOwned};
 use std::cell::Cell;
 use std::default::Default;
 
+use base::id::WebViewId;
 use cssparser::{Parser as CssParser, ParserInput};
 use dom_struct::dom_struct;
 use embedder_traits::EmbedderMsg;
@@ -366,7 +367,7 @@ impl HTMLLinkElement {
 
         // Step 4. Let request be the result of creating a link request given options.
         let url = options.base_url.clone();
-        let Some(request) = options.create_link_request() else {
+        let Some(request) = options.create_link_request(self.owner_window().webview_id()) else {
             // Step 5. If request is null, then return.
             return;
         };
@@ -466,7 +467,7 @@ impl HTMLLinkElement {
             Ok(url) => {
                 let window = document.window();
                 if window.is_top_level() {
-                    let msg = EmbedderMsg::NewFavicon(url.clone());
+                    let msg = EmbedderMsg::NewFavicon(document.webview_id(), url.clone());
                     window.send_to_embedder(msg);
                 }
             },
@@ -626,7 +627,7 @@ impl HTMLLinkElementMethods<crate::DomTypeHolder> for HTMLLinkElement {
 
 impl LinkProcessingOptions {
     /// <https://html.spec.whatwg.org/multipage/#create-a-link-request>
-    fn create_link_request(self) -> Option<RequestBuilder> {
+    fn create_link_request(self, webview_id: WebViewId) -> Option<RequestBuilder> {
         // Step 1. Assert: options's href is not the empty string.
         assert!(!self.href.is_empty());
 
@@ -651,6 +652,7 @@ impl LinkProcessingOptions {
         // FIXME: Step 11. Set request's priority to options's fetch priority.
         // FIXME: Use correct referrer
         let builder = create_a_potential_cors_request(
+            Some(webview_id),
             url,
             destination,
             self.cross_origin,
diff --git a/components/script/dom/htmlmediaelement.rs b/components/script/dom/htmlmediaelement.rs
index c7fd9462b21..b859f06007c 100644
--- a/components/script/dom/htmlmediaelement.rs
+++ b/components/script/dom/htmlmediaelement.rs
@@ -885,6 +885,7 @@ impl HTMLMediaElement {
 
         let cors_setting = cors_setting_for_element(self.upcast());
         let request = create_a_potential_cors_request(
+            Some(document.webview_id()),
             url.clone(),
             destination,
             cors_setting,
diff --git a/components/script/dom/htmlscriptelement.rs b/components/script/dom/htmlscriptelement.rs
index 1aaa0119760..ab00b5356f6 100644
--- a/components/script/dom/htmlscriptelement.rs
+++ b/components/script/dom/htmlscriptelement.rs
@@ -11,7 +11,7 @@ use std::ptr;
 use std::rc::Rc;
 use std::sync::{Arc, Mutex};
 
-use base::id::PipelineId;
+use base::id::{PipelineId, WebViewId};
 use content_security_policy as csp;
 use dom_struct::dom_struct;
 use encoding_rs::Encoding;
@@ -542,6 +542,7 @@ impl PreInvoke for ClassicContext {}
 /// Steps 1-2 of <https://html.spec.whatwg.org/multipage/#fetch-a-classic-script>
 // This function is also used to prefetch a script in `script::dom::servoparser::prefetch`.
 pub(crate) fn script_fetch_request(
+    webview_id: WebViewId,
     url: ServoUrl,
     cors_setting: Option<CorsSettings>,
     origin: ImmutableOrigin,
@@ -551,6 +552,7 @@ pub(crate) fn script_fetch_request(
     // We intentionally ignore options' credentials_mode member for classic scripts.
     // The mode is initialized by create_a_potential_cors_request.
     create_a_potential_cors_request(
+        Some(webview_id),
         url,
         Destination::Script,
         cors_setting,
@@ -576,6 +578,7 @@ fn fetch_a_classic_script(
     // Step 1, 2.
     let doc = script.owner_document();
     let request = script_fetch_request(
+        doc.webview_id(),
         url.clone(),
         cors_setting,
         doc.origin().immutable().clone(),
diff --git a/components/script/dom/htmltextareaelement.rs b/components/script/dom/htmltextareaelement.rs
index e660e3e4d93..c18f245eb87 100644
--- a/components/script/dom/htmltextareaelement.rs
+++ b/components/script/dom/htmltextareaelement.rs
@@ -9,10 +9,10 @@ use std::ops::Range;
 use dom_struct::dom_struct;
 use html5ever::{local_name, namespace_url, ns, LocalName, Prefix};
 use js::rust::HandleObject;
-use script_traits::ScriptToConstellationChan;
 use style::attr::AttrValue;
 use style_dom::ElementState;
 
+use crate::clipboard_provider::EmbedderClipboardProvider;
 use crate::dom::attr::Attr;
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::EventBinding::EventMethods;
@@ -52,7 +52,7 @@ pub(crate) struct HTMLTextAreaElement {
     htmlelement: HTMLElement,
     #[ignore_malloc_size_of = "TextInput contains an IPCSender which cannot be measured"]
     #[no_trace]
-    textinput: DomRefCell<TextInput<ScriptToConstellationChan>>,
+    textinput: DomRefCell<TextInput<EmbedderClipboardProvider>>,
     placeholder: DomRefCell<DOMString>,
     // https://html.spec.whatwg.org/multipage/#concept-textarea-dirty
     value_dirty: Cell<bool>,
@@ -142,7 +142,7 @@ impl HTMLTextAreaElement {
         prefix: Option<Prefix>,
         document: &Document,
     ) -> HTMLTextAreaElement {
-        let chan = document
+        let constellation_sender = document
             .window()
             .as_global_scope()
             .script_to_constellation_chan()
@@ -158,7 +158,10 @@ impl HTMLTextAreaElement {
             textinput: DomRefCell::new(TextInput::new(
                 Lines::Multiple,
                 DOMString::new(),
-                chan,
+                EmbedderClipboardProvider {
+                    constellation_sender,
+                    webview_id: document.webview_id(),
+                },
                 None,
                 None,
                 SelectionDirection::None,
diff --git a/components/script/dom/htmlvideoelement.rs b/components/script/dom/htmlvideoelement.rs
index 974b50a3949..d21a317bd47 100644
--- a/components/script/dom/htmlvideoelement.rs
+++ b/components/script/dom/htmlvideoelement.rs
@@ -223,12 +223,16 @@ impl HTMLVideoElement {
     fn do_fetch_poster_frame(&self, poster_url: ServoUrl, id: PendingImageId, can_gc: CanGc) {
         // Continuation of step 4.
         let document = self.owner_document();
-        let request = RequestBuilder::new(poster_url.clone(), document.global().get_referrer())
-            .destination(Destination::Image)
-            .credentials_mode(CredentialsMode::Include)
-            .use_url_credentials(true)
-            .origin(document.origin().immutable().clone())
-            .pipeline_id(Some(document.global().pipeline_id()));
+        let request = RequestBuilder::new(
+            Some(document.webview_id()),
+            poster_url.clone(),
+            document.global().get_referrer(),
+        )
+        .destination(Destination::Image)
+        .credentials_mode(CredentialsMode::Include)
+        .use_url_credentials(true)
+        .origin(document.origin().immutable().clone())
+        .pipeline_id(Some(document.global().pipeline_id()));
 
         // Step 5.
         // This delay must be independent from the ones created by HTMLMediaElement during
diff --git a/components/script/dom/permissions.rs b/components/script/dom/permissions.rs
index 1d7c8e63698..bcdf42ac63e 100644
--- a/components/script/dom/permissions.rs
+++ b/components/script/dom/permissions.rs
@@ -362,8 +362,12 @@ fn allowed_in_nonsecure_contexts(permission_name: &PermissionName) -> bool {
 }
 
 fn prompt_user_from_embedder(prompt: PermissionPrompt, gs: &GlobalScope) -> PermissionState {
+    let Some(webview_id) = gs.webview_id() else {
+        warn!("Requesting permissions from non-webview-associated global scope");
+        return PermissionState::Denied;
+    };
     let (sender, receiver) = ipc::channel().expect("Failed to create IPC channel!");
-    gs.send_to_embedder(EmbedderMsg::PromptPermission(prompt, sender));
+    gs.send_to_embedder(EmbedderMsg::PromptPermission(webview_id, prompt, sender));
 
     match receiver.recv() {
         Ok(PermissionRequest::Granted) => PermissionState::Granted,
diff --git a/components/script/dom/request.rs b/components/script/dom/request.rs
index 6f672660db5..70fa7b212e5 100644
--- a/components/script/dom/request.rs
+++ b/components/script/dom/request.rs
@@ -108,7 +108,7 @@ impl Request {
 }
 
 fn net_request_from_global(global: &GlobalScope, url: ServoUrl) -> NetTraitsRequest {
-    RequestBuilder::new(url, global.get_referrer())
+    RequestBuilder::new(global.webview_id(), url, global.get_referrer())
         .origin(global.get_url().origin())
         .pipeline_id(Some(global.pipeline_id()))
         .https_state(global.get_https_state())
diff --git a/components/script/dom/serviceworkerglobalscope.rs b/components/script/dom/serviceworkerglobalscope.rs
index aa9184a3dc9..07c44cd11f7 100644
--- a/components/script/dom/serviceworkerglobalscope.rs
+++ b/components/script/dom/serviceworkerglobalscope.rs
@@ -334,7 +334,7 @@ impl ServiceWorkerGlobalScope {
                     .map(Referrer::ReferrerUrl)
                     .unwrap_or_else(|| global.upcast::<GlobalScope>().get_referrer());
 
-                let request = RequestBuilder::new(script_url, referrer)
+                let request = RequestBuilder::new(None, script_url, referrer)
                     .destination(Destination::ServiceWorker)
                     .credentials_mode(CredentialsMode::Include)
                     .parser_metadata(ParserMetadata::NotParserInserted)
diff --git a/components/script/dom/servoparser/prefetch.rs b/components/script/dom/servoparser/prefetch.rs
index 5e394816f44..c67a90372dc 100644
--- a/components/script/dom/servoparser/prefetch.rs
+++ b/components/script/dom/servoparser/prefetch.rs
@@ -4,7 +4,8 @@
 
 use std::cell::{Cell, RefCell};
 
-use base::id::PipelineId;
+use base::id::{PipelineId, WebViewId};
+use content_security_policy::Destination;
 use html5ever::buffer_queue::BufferQueue;
 use html5ever::tokenizer::states::RawKind;
 use html5ever::tokenizer::{
@@ -19,10 +20,9 @@ use servo_url::{ImmutableOrigin, ServoUrl};
 use crate::dom::bindings::reflector::DomObject;
 use crate::dom::bindings::trace::{CustomTraceable, JSTraceable};
 use crate::dom::document::{determine_policy_for_token, Document};
-use crate::dom::htmlimageelement::{image_fetch_request, FromPictureOrSrcSet};
 use crate::dom::htmlscriptelement::script_fetch_request;
+use crate::fetch::create_a_potential_cors_request;
 use crate::script_module::ScriptFetchOptions;
-use crate::stylesheet_loader::stylesheet_fetch_request;
 
 #[derive(JSTraceable, MallocSizeOf)]
 #[cfg_attr(crown, crown::unrooted_must_root_lint::must_root)]
@@ -43,6 +43,7 @@ impl Tokenizer {
         let sink = PrefetchSink {
             origin: document.origin().immutable().clone(),
             pipeline_id: document.global().pipeline_id(),
+            webview_id: document.webview_id(),
             base_url: RefCell::new(None),
             document_url: document.url(),
             referrer: document.global().get_referrer(),
@@ -70,6 +71,8 @@ struct PrefetchSink {
     #[no_trace]
     pipeline_id: PipelineId,
     #[no_trace]
+    webview_id: WebViewId,
+    #[no_trace]
     document_url: ServoUrl,
     #[no_trace]
     base_url: RefCell<Option<ServoUrl>>,
@@ -102,6 +105,7 @@ impl TokenSink for PrefetchSink {
                         .map(|attr| String::from(&attr.value))
                         .unwrap_or_default();
                     let request = script_fetch_request(
+                        self.webview_id,
                         url,
                         cors_setting,
                         self.origin.clone(),
@@ -124,15 +128,18 @@ impl TokenSink for PrefetchSink {
             (TagKind::StartTag, &local_name!("img")) if self.prefetching.get() => {
                 if let Some(url) = self.get_url(tag, local_name!("src")) {
                     debug!("Prefetch {} {}", tag.name, url);
-                    let request = image_fetch_request(
+                    let request = create_a_potential_cors_request(
+                        Some(self.webview_id),
                         url,
-                        self.origin.clone(),
-                        self.referrer.clone(),
-                        self.pipeline_id,
+                        Destination::Image,
                         self.get_cors_settings(tag, local_name!("crossorigin")),
-                        self.get_referrer_policy(tag, local_name!("referrerpolicy")),
-                        FromPictureOrSrcSet::No,
-                    );
+                        None,
+                        self.referrer.clone(),
+                    )
+                    .origin(self.origin.clone())
+                    .pipeline_id(Some(self.pipeline_id))
+                    .referrer_policy(self.get_referrer_policy(tag, local_name!("referrerpolicy")));
+
                     let _ = self
                         .resource_threads
                         .send(CoreResourceMsg::Fetch(request, FetchChannels::Prefetch));
@@ -152,15 +159,21 @@ impl TokenSink for PrefetchSink {
                                 .get_attr(tag, local_name!("integrity"))
                                 .map(|attr| String::from(&attr.value))
                                 .unwrap_or_default();
-                            let request = stylesheet_fetch_request(
+
+                            // https://html.spec.whatwg.org/multipage/#default-fetch-and-process-the-linked-resource
+                            let request = create_a_potential_cors_request(
+                                Some(self.webview_id),
                                 url,
+                                Destination::Style,
                                 cors_setting,
-                                self.origin.clone(),
-                                self.pipeline_id,
+                                None,
                                 self.referrer.clone(),
-                                referrer_policy,
-                                integrity_metadata,
-                            );
+                            )
+                            .origin(self.origin.clone())
+                            .pipeline_id(Some(self.pipeline_id))
+                            .referrer_policy(referrer_policy)
+                            .integrity_metadata(integrity_metadata);
+
                             let _ = self
                                 .resource_threads
                                 .send(CoreResourceMsg::Fetch(request, FetchChannels::Prefetch));
diff --git a/components/script/dom/textcontrol.rs b/components/script/dom/textcontrol.rs
index 184138ab3c0..09f0365fed2 100644
--- a/components/script/dom/textcontrol.rs
+++ b/components/script/dom/textcontrol.rs
@@ -7,8 +7,7 @@
 //!
 //! <https://html.spec.whatwg.org/multipage/#textFieldSelection>
 
-use script_traits::ScriptToConstellationChan;
-
+use crate::clipboard_provider::EmbedderClipboardProvider;
 use crate::dom::bindings::cell::DomRefCell;
 use crate::dom::bindings::codegen::Bindings::HTMLFormElementBinding::SelectionMode;
 use crate::dom::bindings::conversions::DerivedFrom;
@@ -27,13 +26,13 @@ pub(crate) trait TextControlElement: DerivedFrom<EventTarget> + DerivedFrom<Node
 
 pub(crate) struct TextControlSelection<'a, E: TextControlElement> {
     element: &'a E,
-    textinput: &'a DomRefCell<TextInput<ScriptToConstellationChan>>,
+    textinput: &'a DomRefCell<TextInput<EmbedderClipboardProvider>>,
 }
 
 impl<'a, E: TextControlElement> TextControlSelection<'a, E> {
     pub(crate) fn new(
         element: &'a E,
-        textinput: &'a DomRefCell<TextInput<ScriptToConstellationChan>>,
+        textinput: &'a DomRefCell<TextInput<EmbedderClipboardProvider>>,
     ) -> Self {
         TextControlSelection { element, textinput }
     }
diff --git a/components/script/dom/websocket.rs b/components/script/dom/websocket.rs
index ab4303bf863..ad54f06d84d 100644
--- a/components/script/dom/websocket.rs
+++ b/components/script/dom/websocket.rs
@@ -255,7 +255,7 @@ impl WebSocketMethods<crate::DomTypeHolder> for WebSocket {
         let ws = WebSocket::new(global, proto, url_record.clone(), dom_action_sender, can_gc);
         let address = Trusted::new(&*ws);
 
-        let request = RequestBuilder::new(url_record, Referrer::NoReferrer)
+        let request = RequestBuilder::new(global.webview_id(), url_record, Referrer::NoReferrer)
             .origin(global.origin().immutable().clone())
             .mode(RequestMode::WebSocket { protocols });
 
diff --git a/components/script/dom/window.rs b/components/script/dom/window.rs
index e8487f24b95..73ce02a40ab 100644
--- a/components/script/dom/window.rs
+++ b/components/script/dom/window.rs
@@ -17,7 +17,7 @@ use std::time::{Duration, Instant};
 use app_units::Au;
 use backtrace::Backtrace;
 use base::cross_process_instant::CrossProcessInstant;
-use base::id::{BrowsingContextId, PipelineId};
+use base::id::{BrowsingContextId, PipelineId, WebViewId};
 use base64::Engine;
 use bluetooth_traits::BluetoothRequest;
 use canvas_traits::webgl::WebGLChan;
@@ -209,6 +209,11 @@ impl LayoutBlocker {
 #[dom_struct]
 pub(crate) struct Window {
     globalscope: GlobalScope,
+    /// The webview that contains this [`Window`].
+    ///
+    /// This may not be the top-level [`Window`], in the case of frames.
+    #[no_trace]
+    webview_id: WebViewId,
     script_chan: Sender<MainThreadScriptMsg>,
     #[no_trace]
     #[ignore_malloc_size_of = "TODO: Add MallocSizeOf support to layout"]
@@ -391,6 +396,10 @@ pub(crate) struct Window {
 }
 
 impl Window {
+    pub(crate) fn webview_id(&self) -> WebViewId {
+        self.webview_id
+    }
+
     pub(crate) fn as_global_scope(&self) -> &GlobalScope {
         self.upcast::<GlobalScope>()
     }
@@ -726,7 +735,7 @@ impl WindowMethods<crate::DomTypeHolder> for Window {
         let (sender, receiver) =
             ProfiledIpc::channel(self.global().time_profiler_chan().clone()).unwrap();
         let prompt = PromptDefinition::Alert(s.to_string(), sender);
-        let msg = EmbedderMsg::Prompt(prompt, PromptOrigin::Untrusted);
+        let msg = EmbedderMsg::Prompt(self.webview_id(), prompt, PromptOrigin::Untrusted);
         self.send_to_embedder(msg);
         receiver.recv().unwrap();
     }
@@ -736,7 +745,7 @@ impl WindowMethods<crate::DomTypeHolder> for Window {
         let (sender, receiver) =
             ProfiledIpc::channel(self.global().time_profiler_chan().clone()).unwrap();
         let prompt = PromptDefinition::OkCancel(s.to_string(), sender);
-        let msg = EmbedderMsg::Prompt(prompt, PromptOrigin::Untrusted);
+        let msg = EmbedderMsg::Prompt(self.webview_id(), prompt, PromptOrigin::Untrusted);
         self.send_to_embedder(msg);
         receiver.recv().unwrap() == PromptResult::Primary
     }
@@ -746,7 +755,7 @@ impl WindowMethods<crate::DomTypeHolder> for Window {
         let (sender, receiver) =
             ProfiledIpc::channel(self.global().time_profiler_chan().clone()).unwrap();
         let prompt = PromptDefinition::Input(message.to_string(), default.to_string(), sender);
-        let msg = EmbedderMsg::Prompt(prompt, PromptOrigin::Untrusted);
+        let msg = EmbedderMsg::Prompt(self.webview_id(), prompt, PromptOrigin::Untrusted);
         self.send_to_embedder(msg);
         receiver.recv().unwrap().map(|s| s.into())
     }
@@ -1322,7 +1331,7 @@ impl WindowMethods<crate::DomTypeHolder> for Window {
         //TODO determine if this operation is allowed
         let dpr = self.device_pixel_ratio();
         let size = Size2D::new(width, height).to_f32() * dpr;
-        self.send_to_embedder(EmbedderMsg::ResizeTo(size.to_i32()));
+        self.send_to_embedder(EmbedderMsg::ResizeTo(self.webview_id(), size.to_i32()));
     }
 
     // https://drafts.csswg.org/cssom-view/#dom-window-resizeby
@@ -1341,7 +1350,7 @@ impl WindowMethods<crate::DomTypeHolder> for Window {
         //TODO determine if this operation is allowed
         let dpr = self.device_pixel_ratio();
         let point = Point2D::new(x, y).to_f32() * dpr;
-        let msg = EmbedderMsg::MoveTo(point.to_i32());
+        let msg = EmbedderMsg::MoveTo(self.webview_id(), point.to_i32());
         self.send_to_embedder(msg);
     }
 
@@ -2738,6 +2747,7 @@ impl Window {
     #[allow(unsafe_code)]
     #[allow(clippy::too_many_arguments)]
     pub(crate) fn new(
+        webview_id: WebViewId,
         runtime: Rc<Runtime>,
         script_chan: Sender<MainThreadScriptMsg>,
         layout: Box<dyn Layout>,
@@ -2786,6 +2796,7 @@ impl Window {
         ));
 
         let win = Box::new(Self {
+            webview_id,
             globalscope: GlobalScope::new_inherited(
                 pipeline_id,
                 devtools_chan,
diff --git a/components/script/dom/windowproxy.rs b/components/script/dom/windowproxy.rs
index 5f113b5f068..f26180bfc66 100644
--- a/components/script/dom/windowproxy.rs
+++ b/components/script/dom/windowproxy.rs
@@ -292,7 +292,7 @@ impl WindowProxy {
             .and_then(ScriptThread::find_document)
             .map(|doc| DomRoot::from_ref(doc.window()))
             .unwrap();
-        let msg = EmbedderMsg::AllowOpeningWebView(chan);
+        let msg = EmbedderMsg::AllowOpeningWebView(window.webview_id(), chan);
         window.send_to_embedder(msg);
         if let Some(new_top_level_browsing_context_id) = port.recv().unwrap() {
             let new_browsing_context_id =
diff --git a/components/script/dom/workerglobalscope.rs b/components/script/dom/workerglobalscope.rs
index 7db2123e36e..94b709a4fa6 100644
--- a/components/script/dom/workerglobalscope.rs
+++ b/components/script/dom/workerglobalscope.rs
@@ -278,13 +278,17 @@ impl WorkerGlobalScopeMethods<crate::DomTypeHolder> for WorkerGlobalScope {
         rooted!(in(self.runtime.borrow().as_ref().unwrap().cx()) let mut rval = UndefinedValue());
         for url in urls {
             let global_scope = self.upcast::<GlobalScope>();
-            let request = NetRequestInit::new(url.clone(), global_scope.get_referrer())
-                .destination(Destination::Script)
-                .credentials_mode(CredentialsMode::Include)
-                .parser_metadata(ParserMetadata::NotParserInserted)
-                .use_url_credentials(true)
-                .origin(global_scope.origin().immutable().clone())
-                .pipeline_id(Some(self.upcast::<GlobalScope>().pipeline_id()));
+            let request = NetRequestInit::new(
+                global_scope.webview_id(),
+                url.clone(),
+                global_scope.get_referrer(),
+            )
+            .destination(Destination::Script)
+            .credentials_mode(CredentialsMode::Include)
+            .parser_metadata(ParserMetadata::NotParserInserted)
+            .use_url_credentials(true)
+            .origin(global_scope.origin().immutable().clone())
+            .pipeline_id(Some(self.upcast::<GlobalScope>().pipeline_id()));
 
             let (url, source) = match fetch::load_whole_resource(
                 request,
diff --git a/components/script/dom/worklet.rs b/components/script/dom/worklet.rs
index 752aa4e5e9e..527fc47f3ad 100644
--- a/components/script/dom/worklet.rs
+++ b/components/script/dom/worklet.rs
@@ -652,6 +652,7 @@ impl WorkletThread {
         // TODO: Caching.
         let resource_fetcher = self.global_init.resource_threads.sender();
         let request = RequestBuilder::new(
+            None,
             script_url,
             global_scope.upcast::<GlobalScope>().get_referrer(),
         )
diff --git a/components/script/dom/xmlhttprequest.rs b/components/script/dom/xmlhttprequest.rs
index e0eca131d65..5e2bb5abc27 100644
--- a/components/script/dom/xmlhttprequest.rs
+++ b/components/script/dom/xmlhttprequest.rs
@@ -673,6 +673,7 @@ impl XMLHttpRequestMethods<crate::DomTypeHolder> for XMLHttpRequest {
         };
 
         let mut request = RequestBuilder::new(
+            self.global().webview_id(),
             self.request_url.borrow().clone().unwrap(),
             self.referrer.clone(),
         )