Bug 1592026 - Move NativeLayerRoot::CommitToScreen call from PostRender into the compositors. r=jrmuizel

This makes it more similar to how SwapBuffers was used.
This patch also makes us call glFlush directly when using native layers, rather than going through the misleadingly-named GLContext::SwapBuffers method.

Differential Revision: https://phabricator.services.mozilla.com/D57062

--HG--
extra : moz-landing-system : lando

gfx/layers/composite/LayerManagerComposite.cpp

@@ -1296,6 +1296,10 @@ bool LayerManagerComposite::Render(const nsIntRegion& aInvalidRegion,
     AUTO_PROFILER_LABEL("LayerManagerComposite::Render:EndFrame", GRAPHICS);
 
     mCompositor->EndFrame();
+
+    if (usingNativeLayers) {
+      mNativeLayerRoot->CommitToScreen();
+    }
   }
 
   mCompositor->GetWidget()->PostRender(&widgetContext);

gfx/webrender_bindings/RenderCompositorOGL.cpp

@@ -119,10 +119,16 @@ RenderedFrameId RenderCompositorOGL::EndFrame(
     const FfiVec<DeviceIntRect>& aDirtyRects) {
   RenderedFrameId frameId = GetNextRenderFrameId();
   InsertFrameDoneSync();
-  mGL->SwapBuffers();
+
+  if (!mNativeLayerRoot) {
+    mGL->SwapBuffers();
+    return frameId;
+  }
 
   if (mNativeLayerForEntireWindow) {
+    mGL->fFlush();
     mNativeLayerForEntireWindow->NotifySurfaceReady();
+    mNativeLayerRoot->CommitToScreen();
   }
 
   return frameId;
@@ -208,6 +214,8 @@ void RenderCompositorOGL::CompositorEndFrame() {
   mDrawnPixelCount = 0;
 
   mNativeLayerRoot->SetLayers(mAddedLayers);
+  mGL->fFlush();
+  mNativeLayerRoot->CommitToScreen();
   mSurfacePoolHandle->OnEndFrame();
 }
 

widget/cocoa/nsChildView.mm

@@ -1708,11 +1708,7 @@ bool nsChildView::PreRender(WidgetRenderingContext* aContext) {
   return true;
 }
 
-void nsChildView::PostRender(WidgetRenderingContext* aContext) {
+void nsChildView::PostRender(WidgetRenderingContext* aContext) { mViewTearDownLock.Unlock(); }
-  mNativeLayerRoot->CommitToScreen();
-
-  mViewTearDownLock.Unlock();
-}
 
 RefPtr<layers::NativeLayerRoot> nsChildView::GetNativeLayerRoot() { return mNativeLayerRoot; }