Auto merge of #17269 - gterzian:remove_compositor_forwarding_code_and…

…_use_dedicated_mechanism, r=asajeffrey

Remove compositor forwarding code and use dedicated mechanism

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@paulrouget Here is a first sketch of the proposed "design", handling a first message as a proof of concept, if you could please already take a look before I move all the messages(or method calls) across... thanks

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- [ ] `./mach build -d` does not report any errors
- [ ] `./mach test-tidy` does not report any errors
- [ ] These changes fix #15934 (github issue number if applicable).

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- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

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components/canvas/gl_context.rs

@@ -27,7 +27,7 @@ impl GLContextFactory {
             if cfg!(target_os = "windows") {
                 // Used to dispatch functions from the GLContext thread to the main thread's event loop.
                 // Required to allow WGL GLContext sharing in Windows.
-                GLContextFactory::Native(handle, Some(MainThreadDispatcher::new(proxy.clone_compositor_proxy())))
+                GLContextFactory::Native(handle, Some(MainThreadDispatcher::new(proxy.clone())))
             } else {
                 GLContextFactory::Native(handle, None)
             }