Remove the DOMToTexture feature

This relies on WebRender's frame output API, `set_output_image_handler`,
which has been removed from the latest upstream [1]. It's sad to remove
this feature, which was probably a lot of work to implement, but it
seems difficult to patch WebRender to restore this functionality.

Fixes #29936.

1. https://hg.mozilla.org/mozilla-central/rev/361521e3c52324809553c555fb066d50f023d9bf

10 files changed, 36 insertions, 304 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 7fcfe69f26e..b07a73a4ec8 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2171,9 +2171,9 @@ dependencies = [
 
 [[package]]
 name = "gleam"
-version = "0.12.1"
+version = "0.12.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3fdef5b9df6d3a261b80a5ac55e13bf93945725df2463c1b0a2e5a527dce0d37"
+checksum = "a6da1b0a7e3f0833efe2c59f11c0e196d6208735018693c340eded4bd7aacb49"
 dependencies = [
  "gl_generator 0.14.0",
 ]
@@ -2214,9 +2214,9 @@ checksum = "9b919933a397b79c37e33b77bb2aa3dc8eb6e165ad809e58ff75bc7db2e34574"
 
 [[package]]
 name = "glslopt"
-version = "0.1.8"
+version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6c6fe80551c01b577d6f63f2227c485c0cb6827defeaa13dacbf84b42012853"
+checksum = "74a3f5c04450dfdadb4b08f6e5ee6f5110f674de1acbd6199bfec68392a8cbaf"
 dependencies = [
  "cc",
 ]
@@ -2617,9 +2617,9 @@ dependencies = [
 
 [[package]]
 name = "heck"
-version = "0.3.1"
+version = "0.3.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "20564e78d53d2bb135c343b3f47714a56af2061f1c928fdb541dc7b9fdd94205"
+checksum = "6d621efb26863f0e9924c6ac577e8275e5e6b77455db64ffa6c65c904e9e132c"
 dependencies = [
  "unicode-segmentation",
 ]
@@ -2775,16 +2775,17 @@ dependencies = [
 
 [[package]]
 name = "image"
-version = "0.23.10"
+version = "0.23.14"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "985fc06b1304d19c28d5c562ed78ef5316183f2b0053b46763a0b94862373c34"
+checksum = "24ffcb7e7244a9bf19d35bf2883b9c080c4ced3c07a9895572178cdb8f13f6a1"
 dependencies = [
  "bytemuck",
  "byteorder",
+ "color_quant",
  "num-iter",
- "num-rational 0.3.0",
+ "num-rational 0.3.2",
  "num-traits",
- "png 0.16.6",
+ "png 0.16.8",
 ]
 
 [[package]]
@@ -3688,9 +3689,9 @@ dependencies = [
 
 [[package]]
 name = "mio-extras"
-version = "2.0.5"
+version = "2.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46e73a04c2fa6250b8d802134d56d554a9ec2922bf977777c805ea5def61ce40"
+checksum = "52403fe290012ce777c4626790c8951324a2b9e3316b3143779c72b029742f19"
 dependencies = [
  "lazycell",
  "log",
@@ -4043,9 +4044,9 @@ dependencies = [
 
 [[package]]
 name = "num-iter"
-version = "0.1.40"
+version = "0.1.43"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dfb0800a0291891dd9f4fe7bd9c19384f98f7fbe0cd0f39a2c6b88b9868bbc00"
+checksum = "7d03e6c028c5dc5cac6e2dec0efda81fc887605bb3d884578bb6d6bf7514e252"
 dependencies = [
  "autocfg",
  "num-integer",
@@ -4065,9 +4066,9 @@ dependencies = [
 
 [[package]]
 name = "num-rational"
-version = "0.3.0"
+version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a5b4d7360f362cfb50dde8143501e6940b22f644be75a4cc90b2d81968908138"
+checksum = "12ac428b1cb17fce6f731001d307d351ec70a6d202fc2e60f7d4c5e42d8f4f07"
 dependencies = [
  "autocfg",
  "num-integer",
@@ -4571,9 +4572,9 @@ dependencies = [
 
 [[package]]
 name = "png"
-version = "0.16.6"
+version = "0.16.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c150bf7479fafe3dd8740dbe48cc33b2a3efb7b0fe3483aced8bbc39f6d0238d"
+checksum = "3c3287920cb847dee3de33d301c463fba14dda99db24214ddf93f83d3021f4c6"
 dependencies = [
  "bitflags",
  "crc32fast",
@@ -4630,9 +4631,9 @@ checksum = "dbf0c48bc1d91375ae5c3cd81e3722dff1abcf81a30960240640d223f59fe0e5"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.59"
+version = "1.0.63"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6aeca18b86b413c660b781aa319e4e2648a3e6f9eadc9b47e9038e6fe9f3451b"
+checksum = "7b368fba921b0dce7e60f5e04ec15e565b3303972b42bcfde1d0713b881959eb"
 dependencies = [
  "unicode-ident",
 ]
@@ -5296,11 +5297,11 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.64"
+version = "1.0.99"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "799e97dc9fdae36a5c8b8f2cae9ce2ee9fdce2058c57a93e6099d919fd982f79"
+checksum = "46266871c240a00b8f503b877622fe33430b3c7d963bdc0f2adc511e54a1eae3"
 dependencies = [
- "itoa 0.4.8",
+ "itoa 1.0.1",
  "ryu",
  "serde",
 ]
@@ -6619,9 +6620,9 @@ checksum = "1dd624098567895118886609431a7c3b8f516e41d30e0643f03d94592a147e36"
 
 [[package]]
 name = "unicode-width"
-version = "0.1.9"
+version = "0.1.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3ed742d4ea2bd1176e236172c8429aaf54486e7ac098db29ffe6529e0ce50973"
+checksum = "c0edd1e5b14653f783770bce4a4dabb4a5108a5370a5f5d8cfe8710c361f6c8b"
 
 [[package]]
 name = "unicode-xid"
@@ -6999,7 +7000,7 @@ dependencies = [
  "fxhash",
  "gleam",
  "glslopt",
- "image 0.23.10",
+ "image 0.23.14",
  "lazy_static",
  "libc",
  "log",
@@ -7318,9 +7319,9 @@ dependencies = [
 
 [[package]]
 name = "ws"
-version = "0.9.1"
+version = "0.9.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c51a2c47b5798ccc774ffb93ff536aec7c4275d722fd9c740c83cdd1af1f2d94"
+checksum = "25fe90c75f236a0a00247d5900226aea4f2d7b05ccc34da9e7a8880ff59b5848"
 dependencies = [
  "byteorder",
  "bytes 0.4.12",
diff --git a/components/canvas/webgl_mode/inprocess.rs b/components/canvas/webgl_mode/inprocess.rs
index ca9188aee54..64180b47930 100644
--- a/components/canvas/webgl_mode/inprocess.rs
+++ b/components/canvas/webgl_mode/inprocess.rs
@@ -7,12 +7,8 @@ use canvas_traits::webgl::webgl_channel;
 use canvas_traits::webgl::{WebGLContextId, WebGLMsg, WebGLThreads};
 use euclid::default::Size2D;
 use fnv::FnvHashMap;
-use gleam;
-use servo_config::pref;
-use sparkle::gl;
 use sparkle::gl::GlType;
 use std::default::Default;
-use std::rc::Rc;
 use std::sync::{Arc, Mutex};
 use surfman::Device;
 use surfman::SurfaceInfo;
@@ -30,7 +26,6 @@ use webxr_api::LayerGrandManager as WebXRLayerGrandManager;
 pub struct WebGLComm {
     pub webgl_threads: WebGLThreads,
     pub image_handler: Box<dyn WebrenderExternalImageApi>,
-    pub output_handler: Option<Box<dyn webrender_api::OutputImageHandler>>,
     pub webxr_layer_grand_manager: WebXRLayerGrandManager<WebXRSurfman>,
 }
 
@@ -38,7 +33,6 @@ impl WebGLComm {
     /// Creates a new `WebGLComm` object.
     pub fn new(
         surfman: WebrenderSurfman,
-        webrender_gl: Rc<dyn gleam::gl::Gl>,
         webrender_api_sender: webrender_api::RenderApiSender,
         webrender_doc: webrender_api::DocumentId,
         external_images: Arc<Mutex<WebrenderExternalImageRegistry>>,
@@ -64,12 +58,6 @@ impl WebGLComm {
             webxr_init,
         };
 
-        let output_handler = if pref!(dom.webgl.dom_to_texture.enabled) {
-            Some(Box::new(OutputHandler::new(webrender_gl.clone())))
-        } else {
-            None
-        };
-
         let external = WebGLExternalImages::new(surfman, webrender_swap_chains);
 
         WebGLThread::run_on_own_thread(init);
@@ -77,7 +65,6 @@ impl WebGLComm {
         WebGLComm {
             webgl_threads: WebGLThreads(sender),
             image_handler: Box::new(external),
-            output_handler: output_handler.map(|b| b as Box<_>),
             webxr_layer_grand_manager: webxr_layer_grand_manager,
         }
     }
@@ -144,43 +131,3 @@ impl WebrenderExternalImageApi for WebGLExternalImages {
         self.unlock_swap_chain(id);
     }
 }
-
-/// struct used to implement DOMToTexture feature and webrender::OutputImageHandler trait.
-struct OutputHandler {
-    webrender_gl: Rc<dyn gleam::gl::Gl>,
-    sync_objects: FnvHashMap<webrender_api::PipelineId, gleam::gl::GLsync>,
-}
-
-impl OutputHandler {
-    fn new(webrender_gl: Rc<dyn gleam::gl::Gl>) -> Self {
-        OutputHandler {
-            webrender_gl,
-            sync_objects: Default::default(),
-        }
-    }
-}
-
-/// Bridge between the WR frame outputs and WebGL to implement DOMToTexture synchronization.
-impl webrender_api::OutputImageHandler for OutputHandler {
-    fn lock(
-        &mut self,
-        id: webrender_api::PipelineId,
-    ) -> Option<(u32, webrender_api::units::FramebufferIntSize)> {
-        // Insert a fence in the WR command queue
-        let gl_sync = self
-            .webrender_gl
-            .fence_sync(gl::SYNC_GPU_COMMANDS_COMPLETE, 0);
-        self.sync_objects.insert(id, gl_sync);
-        // https://github.com/servo/servo/issues/24615
-        None
-    }
-
-    fn unlock(&mut self, id: webrender_api::PipelineId) {
-        if let Some(gl_sync) = self.sync_objects.remove(&id) {
-            // Flush the Sync object into the GPU's command queue to guarantee that it it's signaled.
-            self.webrender_gl.flush();
-            // Mark the sync object for deletion.
-            self.webrender_gl.delete_sync(gl_sync);
-        }
-    }
-}
diff --git a/components/canvas/webgl_thread.rs b/components/canvas/webgl_thread.rs
index c764fc69b77..27809ae957e 100644
--- a/components/canvas/webgl_thread.rs
+++ b/components/canvas/webgl_thread.rs
@@ -10,7 +10,6 @@ use canvas_traits::webgl::ActiveAttribInfo;
 use canvas_traits::webgl::ActiveUniformBlockInfo;
 use canvas_traits::webgl::ActiveUniformInfo;
 use canvas_traits::webgl::AlphaTreatment;
-use canvas_traits::webgl::DOMToTextureCommand;
 use canvas_traits::webgl::GLContextAttributes;
 use canvas_traits::webgl::GLLimits;
 use canvas_traits::webgl::GlType;
@@ -239,8 +238,6 @@ pub(crate) struct WebGLThread {
     cached_context_info: FnvHashMap<WebGLContextId, WebGLContextInfo>,
     /// Current bound context.
     bound_context_id: Option<WebGLContextId>,
-    /// Texture ids and sizes used in DOM to texture outputs.
-    dom_outputs: FnvHashMap<webrender_api::PipelineId, DOMToTextureData>,
     /// List of registered webrender external images.
     /// We use it to get an unique ID for new WebGLContexts.
     external_images: Arc<Mutex<WebrenderExternalImageRegistry>>,
@@ -298,7 +295,6 @@ impl WebGLThread {
             contexts: Default::default(),
             cached_context_info: Default::default(),
             bound_context_id: None,
-            dom_outputs: Default::default(),
             external_images,
             sender,
             receiver: receiver.into_inner(),
@@ -410,9 +406,6 @@ impl WebGLThread {
             WebGLMsg::SwapBuffers(swap_ids, sender, sent_time) => {
                 self.handle_swap_buffers(swap_ids, sender, sent_time);
             },
-            WebGLMsg::DOMToTextureCommand(command) => {
-                self.handle_dom_to_texture(command);
-            },
             WebGLMsg::Exit => {
                 return true;
             },
@@ -890,88 +883,6 @@ impl WebGLThread {
         SurfaceAccess::GPUOnly
     }
 
-    fn handle_dom_to_texture(&mut self, command: DOMToTextureCommand) {
-        match command {
-            DOMToTextureCommand::Attach(context_id, texture_id, document_id, pipeline_id, size) => {
-                let data = Self::make_current_if_needed(
-                    &self.device,
-                    context_id,
-                    &self.contexts,
-                    &mut self.bound_context_id,
-                )
-                .expect("WebGLContext not found in a WebGL DOMToTextureCommand::Attach command");
-                // Initialize the texture that WR will use for frame outputs.
-                data.gl.tex_image_2d(
-                    gl::TEXTURE_2D,
-                    0,
-                    gl::RGBA as gl::GLint,
-                    size.width,
-                    size.height,
-                    0,
-                    gl::RGBA,
-                    gl::UNSIGNED_BYTE,
-                    gl::TexImageSource::Pixels(None),
-                );
-                self.dom_outputs.insert(
-                    pipeline_id,
-                    DOMToTextureData {
-                        context_id,
-                        texture_id,
-                        document_id,
-                        size,
-                    },
-                );
-                let mut txn = webrender_api::Transaction::new();
-                txn.enable_frame_output(pipeline_id, true);
-                self.webrender_api.send_transaction(document_id, txn);
-            },
-            DOMToTextureCommand::Lock(pipeline_id, gl_sync, sender) => {
-                let result = self.handle_dom_to_texture_lock(pipeline_id, gl_sync);
-                // Send the texture id and size to WR.
-                sender.send(result).unwrap();
-            },
-            DOMToTextureCommand::Detach(texture_id) => {
-                if let Some((pipeline_id, document_id)) = self
-                    .dom_outputs
-                    .iter()
-                    .find(|&(_, v)| v.texture_id == texture_id)
-                    .map(|(k, v)| (*k, v.document_id))
-                {
-                    let mut txn = webrender_api::Transaction::new();
-                    txn.enable_frame_output(pipeline_id, false);
-                    self.webrender_api.send_transaction(document_id, txn);
-                    self.dom_outputs.remove(&pipeline_id);
-                }
-            },
-        }
-    }
-
-    pub(crate) fn handle_dom_to_texture_lock(
-        &mut self,
-        pipeline_id: webrender_api::PipelineId,
-        gl_sync: usize,
-    ) -> Option<(u32, Size2D<i32>)> {
-        let device = &self.device;
-        let contexts = &self.contexts;
-        let bound_context_id = &mut self.bound_context_id;
-        self.dom_outputs.get(&pipeline_id).and_then(|dom_data| {
-            let data = Self::make_current_if_needed(
-                device,
-                dom_data.context_id,
-                contexts,
-                bound_context_id,
-            );
-            data.and_then(|data| {
-                // The next glWaitSync call is used to synchronize the two flows of
-                // OpenGL commands (WR and WebGL) in order to avoid using semi-ready WR textures.
-                // glWaitSync doesn't block WebGL CPU thread.
-                data.gl
-                    .wait_sync(gl_sync as gl::GLsync, 0, gl::TIMEOUT_IGNORED);
-                Some((dom_data.texture_id.get(), dom_data.size))
-            })
-        })
-    }
-
     /// Gets a reference to a Context for a given WebGLContextId and makes it current if required.
     fn make_current_if_needed<'a>(
         device: &Device,
@@ -1106,14 +1017,6 @@ fn current_wr_texture_target(device: &Device) -> webrender_api::TextureTarget {
     }
 }
 
-/// Data about the linked DOM<->WebGLTexture elements.
-struct DOMToTextureData {
-    context_id: WebGLContextId,
-    texture_id: WebGLTextureId,
-    document_id: webrender_api::DocumentId,
-    size: Size2D<i32>,
-}
-
 /// WebGL Commands Implementation
 pub struct WebGLImpl;
 
diff --git a/components/canvas_traits/webgl.rs b/components/canvas_traits/webgl.rs
index 175e5ab0937..0ea7fb1edde 100644
--- a/components/canvas_traits/webgl.rs
+++ b/components/canvas_traits/webgl.rs
@@ -11,7 +11,7 @@ use std::borrow::Cow;
 use std::fmt;
 use std::num::{NonZeroU32, NonZeroU64};
 use std::ops::Deref;
-use webrender_api::{DocumentId, ImageKey, PipelineId};
+use webrender_api::ImageKey;
 use webxr_api::ContextId as WebXRContextId;
 use webxr_api::Error as WebXRError;
 use webxr_api::LayerId as WebXRLayerId;
@@ -76,8 +76,6 @@ pub enum WebGLMsg {
     /// Runs a WebXRCommand (WebXR layers need to be created in the WebGL
     /// thread, as they may have thread affinity).
     WebXRCommand(WebXRCommand),
-    /// Commands used for the DOMToTexture feature.
-    DOMToTextureCommand(DOMToTextureCommand),
     /// Performs a buffer swap.
     ///
     /// The third field contains the time (in ns) when the request
@@ -174,10 +172,6 @@ impl WebGLMsgSender {
     pub fn send_remove(&self) -> WebGLSendResult {
         self.sender.send(WebGLMsg::RemoveContext(self.ctx_id))
     }
-
-    pub fn send_dom_to_texture(&self, command: DOMToTextureCommand) -> WebGLSendResult {
-        self.sender.send(WebGLMsg::DOMToTextureCommand(command))
-    }
 }
 
 #[derive(Deserialize, Serialize)]
@@ -662,23 +656,6 @@ pub enum WebGLFramebufferBindingRequest {
 
 pub type WebGLResult<T> = Result<T, WebGLError>;
 
-/// WebGL commands required to implement DOMToTexture feature.
-#[derive(Clone, Debug, Deserialize, Serialize)]
-pub enum DOMToTextureCommand {
-    /// Attaches a HTMLIFrameElement to a WebGLTexture.
-    Attach(
-        WebGLContextId,
-        WebGLTextureId,
-        DocumentId,
-        PipelineId,
-        Size2D<i32>,
-    ),
-    /// Releases the HTMLIFrameElement to WebGLTexture attachment.
-    Detach(WebGLTextureId),
-    /// Lock message used for a correct synchronization with WebRender GL flow.
-    Lock(PipelineId, usize, WebGLSender<Option<(u32, Size2D<i32>)>>),
-}
-
 /// Information about a WebGL program linking operation.
 #[derive(Clone, Debug, Deserialize, Serialize)]
 pub struct ProgramLinkInfo {
diff --git a/components/config/prefs.rs b/components/config/prefs.rs
index d72e64ad7c8..a9e1cd85d1b 100644
--- a/components/config/prefs.rs
+++ b/components/config/prefs.rs
@@ -259,11 +259,6 @@ mod gen {
                     #[serde(default)]
                     enabled: bool,
                 },
-                webgl: {
-                    dom_to_texture: {
-                        enabled: bool,
-                    }
-                },
                 webgl2: {
                     enabled: bool,
                 },
diff --git a/components/script/dom/webglrenderingcontext.rs b/components/script/dom/webglrenderingcontext.rs
index de5d01909a9..2a9c3584a89 100644
--- a/components/script/dom/webglrenderingcontext.rs
+++ b/components/script/dom/webglrenderingcontext.rs
@@ -24,7 +24,6 @@ use crate::dom::element::cors_setting_for_element;
 use crate::dom::event::{Event, EventBubbles, EventCancelable};
 use crate::dom::htmlcanvaselement::utils as canvas_utils;
 use crate::dom::htmlcanvaselement::{HTMLCanvasElement, LayoutCanvasRenderingContextHelpers};
-use crate::dom::htmliframeelement::HTMLIFrameElement;
 use crate::dom::node::{document_from_node, window_from_node, Node, NodeDamage};
 use crate::dom::promise::Promise;
 use crate::dom::vertexarrayobject::VertexAttribData;
@@ -57,11 +56,11 @@ use crate::script_runtime::JSContext as SafeJSContext;
 use backtrace::Backtrace;
 use canvas_traits::webgl::WebGLError::*;
 use canvas_traits::webgl::{
-    webgl_channel, AlphaTreatment, DOMToTextureCommand, GLContextAttributes, GLLimits, GlType,
-    Parameter, SizedDataType, TexDataType, TexFormat, TexParameter, WebGLChan, WebGLCommand,
-    WebGLCommandBacktrace, WebGLContextId, WebGLError, WebGLFramebufferBindingRequest, WebGLMsg,
-    WebGLMsgSender, WebGLProgramId, WebGLResult, WebGLSLVersion, WebGLSendResult, WebGLSender,
-    WebGLVersion, YAxisTreatment,
+    webgl_channel, AlphaTreatment, GLContextAttributes, GLLimits, GlType, Parameter, SizedDataType,
+    TexDataType, TexFormat, TexParameter, WebGLChan, WebGLCommand, WebGLCommandBacktrace,
+    WebGLContextId, WebGLError, WebGLFramebufferBindingRequest, WebGLMsg, WebGLMsgSender,
+    WebGLProgramId, WebGLResult, WebGLSLVersion, WebGLSendResult, WebGLSender, WebGLVersion,
+    YAxisTreatment,
 };
 use dom_struct::dom_struct;
 use embedder_traits::EventLoopWaker;
@@ -379,10 +378,6 @@ impl WebGLRenderingContext {
         }
     }
 
-    pub(crate) fn webgl_sender(&self) -> WebGLMessageSender {
-        self.webgl_sender.clone()
-    }
-
     pub fn context_id(&self) -> WebGLContextId {
         self.webgl_sender.context_id()
     }
@@ -4435,60 +4430,6 @@ impl WebGLRenderingContextMethods for WebGLRenderingContext {
     }
 
     // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
-    fn TexImageDOM(
-        &self,
-        target: u32,
-        level: i32,
-        internal_format: u32,
-        width: i32,
-        height: i32,
-        format: u32,
-        data_type: u32,
-        source: &HTMLIFrameElement,
-    ) -> ErrorResult {
-        // Currently DOMToTexture only supports TEXTURE_2D, RGBA, UNSIGNED_BYTE and no levels.
-        if target != constants::TEXTURE_2D ||
-            level != 0 ||
-            internal_format != constants::RGBA ||
-            format != constants::RGBA ||
-            data_type != constants::UNSIGNED_BYTE
-        {
-            return Ok(self.webgl_error(InvalidValue));
-        }
-
-        // Get bound texture
-        let texture = handle_potential_webgl_error!(
-            self,
-            self.textures
-                .active_texture_slot(constants::TEXTURE_2D, self.webgl_version())
-                .unwrap()
-                .get()
-                .ok_or(InvalidOperation),
-            return Ok(())
-        );
-
-        let pipeline_id = source.pipeline_id().ok_or(Error::InvalidState)?;
-        let document_id = self
-            .global()
-            .downcast::<Window>()
-            .ok_or(Error::InvalidState)?
-            .webrender_document();
-
-        texture.set_attached_to_dom();
-
-        let command = DOMToTextureCommand::Attach(
-            self.webgl_sender.context_id(),
-            texture.id(),
-            document_id,
-            pipeline_id.to_webrender(),
-            Size2D::new(width, height),
-        );
-        self.webgl_sender.send_dom_to_texture(command).unwrap();
-
-        Ok(())
-    }
-
-    // https://www.khronos.org/registry/webgl/specs/latest/1.0/#5.14.8
     #[allow(unsafe_code)]
     fn TexSubImage2D(
         &self,
@@ -5013,10 +4954,6 @@ impl WebGLMessageSender {
     pub fn send_remove(&self) -> WebGLSendResult {
         self.wake_after_send(|| self.sender.send_remove())
     }
-
-    pub fn send_dom_to_texture(&self, command: DOMToTextureCommand) -> WebGLSendResult {
-        self.wake_after_send(|| self.sender.send_dom_to_texture(command))
-    }
 }
 
 pub trait Size2DExt {
diff --git a/components/script/dom/webgltexture.rs b/components/script/dom/webgltexture.rs
index 7456f772dec..ccb005cc393 100644
--- a/components/script/dom/webgltexture.rs
+++ b/components/script/dom/webgltexture.rs
@@ -20,7 +20,7 @@ use canvas_traits::webgl::{
     webgl_channel, TexDataType, TexFormat, TexParameter, TexParameterBool, TexParameterInt,
     WebGLResult, WebGLTextureId,
 };
-use canvas_traits::webgl::{DOMToTextureCommand, WebGLCommand, WebGLError};
+use canvas_traits::webgl::{WebGLCommand, WebGLError};
 use dom_struct::dom_struct;
 use std::cell::Cell;
 use std::cmp;
@@ -62,8 +62,6 @@ pub struct WebGLTexture {
     // Store information for min and mag filters
     min_filter: Cell<u32>,
     mag_filter: Cell<u32>,
-    /// True if this texture is used for the DOMToTexture feature.
-    attached_to_dom: Cell<bool>,
     /// Framebuffer that this texture is attached to.
     attached_framebuffer: MutNullableDom<WebGLFramebuffer>,
     /// Number of immutable levels.
@@ -90,7 +88,6 @@ impl WebGLTexture {
             min_filter: Cell::new(constants::NEAREST_MIPMAP_LINEAR),
             mag_filter: Cell::new(constants::LINEAR),
             image_info_array: DomRefCell::new([None; MAX_LEVEL_COUNT * MAX_FACE_COUNT]),
-            attached_to_dom: Cell::new(false),
             attached_framebuffer: Default::default(),
         }
     }
@@ -224,12 +221,6 @@ impl WebGLTexture {
         if !self.is_deleted.get() {
             self.is_deleted.set(true);
             let context = self.upcast::<WebGLObject>().context();
-            // Notify WR to release the frame output when using DOMToTexture feature
-            if self.attached_to_dom.get() {
-                let _ = context
-                    .webgl_sender()
-                    .send_dom_to_texture(DOMToTextureCommand::Detach(self.id));
-            }
 
             /*
             If a texture object is deleted while its image is attached to one or more attachment
@@ -469,10 +460,6 @@ impl WebGLTexture {
         self.image_info_at_face(0, self.base_mipmap_level)
     }
 
-    pub fn set_attached_to_dom(&self) {
-        self.attached_to_dom.set(true);
-    }
-
     pub fn attach_to_framebuffer(&self, fb: &WebGLFramebuffer) {
         self.attached_framebuffer.set(Some(fb));
     }
diff --git a/components/script/dom/webidls/WebGLRenderingContext.webidl b/components/script/dom/webidls/WebGLRenderingContext.webidl
index f54dfd67507..fcd3f9752ae 100644
--- a/components/script/dom/webidls/WebGLRenderingContext.webidl
+++ b/components/script/dom/webidls/WebGLRenderingContext.webidl
@@ -680,16 +680,9 @@ interface mixin WebGLRenderingContextOverloads
     undefined uniformMatrix4fv(WebGLUniformLocation? location, GLboolean transpose, Float32List value);
 };
 
-interface mixin WebGLRenderingContextExtensions {
-    [Throws, Pref="dom.webgl.dom_to_texture.enabled"]
-    undefined texImageDOM(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height,
-                     GLenum format, GLenum type, HTMLIFrameElement source); // May throw DOMException
-};
-
 [Exposed=(Window)]
 interface WebGLRenderingContext
 {
 };
 WebGLRenderingContext includes WebGLRenderingContextBase;
 WebGLRenderingContext includes WebGLRenderingContextOverloads;
-WebGLRenderingContext includes WebGLRenderingContextExtensions;
diff --git a/components/servo/lib.rs b/components/servo/lib.rs
index 65b84721006..434ebe5b33e 100644
--- a/components/servo/lib.rs
+++ b/components/servo/lib.rs
@@ -440,10 +440,8 @@ where
             webgl_threads,
             webxr_layer_grand_manager,
             image_handler,
-            output_handler,
         } = WebGLComm::new(
             webrender_surfman.clone(),
-            webrender_gl.clone(),
             webrender_api.create_sender(),
             webrender_document,
             external_images.clone(),
@@ -453,11 +451,6 @@ where
         // Set webrender external image handler for WebGL textures
         external_image_handlers.set_handler(image_handler, WebrenderImageHandlerType::WebGL);
 
-        // Set DOM to texture handler, if enabled.
-        if let Some(output_handler) = output_handler {
-            webrender.set_output_image_handler(output_handler);
-        }
-
         // Create the WebXR main thread
         let mut webxr_main_thread =
             webxr::MainThreadRegistry::new(event_loop_waker, webxr_layer_grand_manager)
diff --git a/resources/prefs.json b/resources/prefs.json
index f093171c6ee..68d9cbb89e0 100644
--- a/resources/prefs.json
+++ b/resources/prefs.json
@@ -30,7 +30,6 @@
   "dom.testable_crash.enabled": false,
   "dom.testbinding.enabled": false,
   "dom.testing.htmlinputelement.select_files.enabled": false,
-  "dom.webgl.dom_to_texture.enabled": false,
   "dom.webgl2.enabled": false,
   "dom.webgpu.enabled": false,
   "dom.webrtc.enabled": false,