Auto merge of #17685 - paulrouget:rm_InitializeCompositing, r=jdm

remove no-op InitializeCompositing message

I think this is no-op.

---
<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [ ] These changes fix #__ (github issue number if applicable).

<!-- Either: -->
- [ ] There are tests for these changes OR
- [ ] These changes do not require tests because _____

<!-- Also, please make sure that "Allow edits from maintainers" checkbox is checked, so that we can help you if you get stuck somewhere along the way.-->

<!-- Pull requests that do not address these steps are welcome, but they will require additional verification as part of the review process. -->

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/17685)
<!-- Reviewable:end -->

components/compositing/compositor.rs

@@ -742,10 +742,6 @@ impl<Window: WindowMethods> IOCompositor<Window> {
                 self.composite();
             }
 
-            WindowEvent::InitializeCompositing => {
-                self.initialize_compositing();
-            }
-
             WindowEvent::Resize(size) => {
                 self.on_resize_window_event(size);
             }
@@ -1566,9 +1562,6 @@ impl<Window: WindowMethods> IOCompositor<Window> {
         }
     }
 
-    fn initialize_compositing(&mut self) {
-    }
-
     fn get_root_pipeline_id(&self) -> Option<PipelineId> {
         self.root_pipeline.as_ref().map(|pipeline| pipeline.id)
     }

components/compositing/windowing.rs

@@ -44,9 +44,6 @@ pub enum WindowEvent {
     /// Sent when part of the window is marked dirty and needs to be redrawn. Before sending this
     /// message, the window must make the same GL context as in `PrepareRenderingEvent` current.
     Refresh,
-    /// Sent to initialize the GL context. The windowing system must have a valid, current GL
-    /// context when this message is sent.
-    InitializeCompositing,
     /// Sent when the window is resized.
     Resize(TypedSize2D<u32, DevicePixel>),
     /// Touchpad Pressure
@@ -85,7 +82,6 @@ impl Debug for WindowEvent {
         match *self {
             WindowEvent::Idle => write!(f, "Idle"),
             WindowEvent::Refresh => write!(f, "Refresh"),
-            WindowEvent::InitializeCompositing => write!(f, "InitializeCompositing"),
             WindowEvent::Resize(..) => write!(f, "Resize"),
             WindowEvent::TouchpadPressure(..) => write!(f, "TouchpadPressure"),
             WindowEvent::KeyEvent(..) => write!(f, "Key"),

ports/cef/browser_host.rs

@@ -486,8 +486,7 @@ full_cef_class_impl! {
             this.downcast().send_window_event(WindowEvent::PinchZoom((new_zoom_level / old_zoom_level) as f32))
         }}
 
-        fn initialize_compositing(&this,) -> () {{
-            this.downcast().send_window_event(WindowEvent::InitializeCompositing);
+        fn initialize_compositing(&_this,) -> () {{
         }}
 
         fn composite(&this,) -> () {{

ports/servo/main.rs

@@ -165,8 +165,6 @@ fn main() {
 
     register_glutin_resize_handler(&window, &mut browser);
 
-    browser.browser.handle_events(vec![WindowEvent::InitializeCompositing]);
-
     // Feed events from the window to the browser until the browser
     // says to stop.
     loop {