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

content/browser/renderer_host/render_widget_host_impl.cc

Index: content/browser/renderer_host/render_widget_host_impl.cc
diff --git a/content/browser/renderer_host/render_widget_host_impl.cc b/content/browser/renderer_host/render_widget_host_impl.cc
index 013d4392c7df949c2c7a5b6e2b8ce6aed81b4912..d4395031c102208fcc016fdd09f71e297b4e6dff 100644
--- a/content/browser/renderer_host/render_widget_host_impl.cc
+++ b/content/browser/renderer_host/render_widget_host_impl.cc
@@ -554,6 +554,8 @@ bool RenderWidgetHostImpl::OnMessageReceived(const IPC::Message &msg) {
     IPC_MESSAGE_HANDLER(ViewHostMsg_SetTooltipText, OnSetTooltipText)
     IPC_MESSAGE_HANDLER_GENERIC(ViewHostMsg_SwapCompositorFrame,
                                 OnSwapCompositorFrame(msg))
+    IPC_MESSAGE_HANDLER(ViewHostMsg_BeginFrameDidNotDraw,
+                        OnBeginFrameDidNotDraw)

[brianderson, 2017/03/13 22:55:39]

Here and elsewhere: Can you call this OnBeginFrameDidNotSwap? In the future it's
possible we split out draw from swap. In such a world, we'd want to send a
DidNotSwap message even if we already drew.

[Eric Seckler, 2017/03/14 11:13:41]

Done.

     IPC_MESSAGE_HANDLER(ViewHostMsg_UpdateRect, OnUpdateRect)
     IPC_MESSAGE_HANDLER(ViewHostMsg_SetCursor, OnSetCursor)
     IPC_MESSAGE_HANDLER(ViewHostMsg_TextInputStateChanged,
@@ -1863,6 +1865,12 @@ bool RenderWidgetHostImpl::OnSwapCompositorFrame(
   return true;
 }
 
+void RenderWidgetHostImpl::OnBeginFrameDidNotDraw(
+    const cc::BeginFrameAck& ack) {
+  if (view_)
+    view_->OnBeginFrameDidNotDraw(ack);

[brianderson, 2017/03/13 22:55:39]

Since this is conditional, should the state in the View tracking
latest_confirmed_begin_frame_sequence_number_ be tracked here instead?

Or at least initialized in RWHI::SetView?

[Eric Seckler, 2017/03/14 11:13:41]

I don't think we can track the lcbfsn in RWHI, since it doesn't know anything
about DFH.

A view is also never "reused", i.e. detached from a RWHI and then re-attached
later. It's always constructed for a single RWHI (a pointer to RWH/RWHI is
provided in constructor). Thus, I don't think resetting the tracking during
RWHI::SetView makes a difference.

It also sounded like Fady wants to get rid of skipping drawing in DFH, so maybe
we can remove the tracking of lcbfsn in the RWHVs soon anyway.

+}
+
 void RenderWidgetHostImpl::OnUpdateRect(
     const ViewHostMsg_UpdateRect_Params& params) {
   TRACE_EVENT0("renderer_host", "RenderWidgetHostImpl::OnUpdateRect");