Bug 1377688 - Remove RenderThread::NewScrollFrameReady() r=kats

WebRenderBridgeParent::CompositeToTarget() calls WebRenderAPI::GenerateFrame() if it is necessary to trigger UpdateAndRender(). It is not necessary to trigger UpdateAndRender() by new_scroll_frame_ready

gfx/webrender_bindings/RenderThread.cpp

@@ -170,26 +170,6 @@ RenderThread::NewFrameReady(wr::WindowId aWindowId)
   DecPendingFrameCount(aWindowId);
 }
 
-void
-RenderThread::NewScrollFrameReady(wr::WindowId aWindowId, bool aCompositeNeeded)
-{
-  if (mHasShutdown) {
-    return;
-  }
-
-  if (!IsInRenderThread()) {
-    Loop()->PostTask(NewRunnableMethod<wr::WindowId, bool>(
-      "wr::RenderThread::NewScrollFrameReady",
-      this,
-      &RenderThread::NewScrollFrameReady,
-      aWindowId,
-      aCompositeNeeded));
-    return;
-  }
-
-  UpdateAndRender(aWindowId);
-}
-
 void
 RenderThread::RunEvent(wr::WindowId aWindowId, UniquePtr<RendererEvent> aEvent)
 {
@@ -404,8 +384,10 @@ void wr_notifier_new_frame_ready(WrWindowId aWindowId)
 
 void wr_notifier_new_scroll_frame_ready(WrWindowId aWindowId, bool aCompositeNeeded)
 {
-  mozilla::wr::RenderThread::Get()->NewScrollFrameReady(mozilla::wr::WindowId(aWindowId),
-                                                        aCompositeNeeded);
+  // It is not necessary to update rendering with new_scroll_frame_ready.
+  // WebRenderBridgeParent::CompositeToTarget() is implemented to call
+  // WebRenderAPI::GenerateFrame() if it is necessary to trigger UpdateAndRender().
+  // See Bug 1377688.
 }
 
 void wr_notifier_external_event(WrWindowId aWindowId, size_t aRawEvent)

gfx/webrender_bindings/RenderThread.h

@@ -106,9 +106,6 @@ public:
   /// Automatically forwarded to the render thread.
   void NewFrameReady(wr::WindowId aWindowId);
 
-  /// Automatically forwarded to the render thread.
-  void NewScrollFrameReady(wr::WindowId aWindowId, bool aCompositeNeeded);
-
   /// Automatically forwarded to the render thread.
   void PipelineSizeChanged(wr::WindowId aWindowId, uint64_t aPipelineId, float aWidth, float aHeight);