cc: Introduce BeginFrame sequence numbers and acknowledgements.

content/browser/frame_host/render_widget_host_view_child_frame.cc

Index: content/browser/frame_host/render_widget_host_view_child_frame.cc
diff --git a/content/browser/frame_host/render_widget_host_view_child_frame.cc b/content/browser/frame_host/render_widget_host_view_child_frame.cc
index 56e95b8775151d8ae88efa65e29b402e7919ef80..8fc135be1426b49917ad15bb1a89fbd755c76172 100644
--- a/content/browser/frame_host/render_widget_host_view_child_frame.cc
+++ b/content/browser/frame_host/render_widget_host_view_child_frame.cc
@@ -404,6 +404,10 @@ void RenderWidgetHostViewChildFrame::OnSwapCompositorFrame(
     allocated_new_local_frame_id = true;
   }
 
+  uint64_t begin_frame_source_id = frame.metadata.begin_frame_source_id;
+  uint64_t begin_frame_number = frame.metadata.begin_frame_number;
+  uint64_t latest_confirmed_frame = frame.metadata.latest_confirmed_frame;
+
   cc::SurfaceFactory::DrawCallback ack_callback =
       base::Bind(&RenderWidgetHostViewChildFrame::SurfaceDrawn, AsWeakPtr(),
                  compositor_frame_sink_id);
@@ -426,6 +430,14 @@ void RenderWidgetHostViewChildFrame::OnSwapCompositorFrame(
         scale_factor, sequence);
   }
   ProcessFrameSwappedCallbacks();
+  DidSwapFrame(begin_frame_source_id, begin_frame_number,
+               latest_confirmed_frame);
+}
+
+void RenderWidgetHostViewChildFrame::OnBeginFrameDidNotDraw(
+    const cc::BeginFrameAck& ack) {
+  if (begin_frame_source_)
+    begin_frame_source_->DidFinishFrame(this, ack);
 }
 
 void RenderWidgetHostViewChildFrame::ProcessFrameSwappedCallbacks() {
@@ -437,6 +449,16 @@ void RenderWidgetHostViewChildFrame::ProcessFrameSwappedCallbacks() {
     callback->Run();
 }
 
+void RenderWidgetHostViewChildFrame::DidSwapFrame(
+    uint64_t source_id,
+    uint64_t sequence_number,
+    uint64_t latest_confirmed_frame) {
+  cc::BeginFrameAck ack(source_id, sequence_number, latest_confirmed_frame,
+                        0, true);
+  if (begin_frame_source_)
+    begin_frame_source_->DidFinishFrame(this, ack);
+}
+
 gfx::Rect RenderWidgetHostViewChildFrame::GetBoundsInRootWindow() {
   gfx::Rect rect;
   if (frame_connector_) {