[cc] Pass on BeginFrameAcks from CompositorEBFS through RWHVAura, DFH.

content/renderer/gpu/renderer_compositor_frame_sink.cc

Index: content/renderer/gpu/renderer_compositor_frame_sink.cc
diff --git a/content/renderer/gpu/renderer_compositor_frame_sink.cc b/content/renderer/gpu/renderer_compositor_frame_sink.cc
index 16ccae09e0618e338d0de11d2f4676883ea6cb42..8a1ba5bc9a2843fc19d8967077d7c421ae712dd5 100644
--- a/content/renderer/gpu/renderer_compositor_frame_sink.cc
+++ b/content/renderer/gpu/renderer_compositor_frame_sink.cc
@@ -109,6 +109,9 @@ void RendererCompositorFrameSink::DetachFromClient() {
 
 void RendererCompositorFrameSink::SubmitCompositorFrame(
     cc::CompositorFrame frame) {
+  // We should only submit CompositorFrames with valid BeginFrameAcks.
+  DCHECK_LE(cc::BeginFrameArgs::kStartingFrameNumber,
+            frame.metadata.begin_frame_ack.sequence_number);
   {
     std::unique_ptr<FrameSwapMessageQueue::SendMessageScope>
         send_message_scope =