Support distributing vsync info with surfaces.

content/browser/compositor/onscreen_display_client.cc

Index: content/browser/compositor/onscreen_display_client.cc
diff --git a/content/browser/compositor/onscreen_display_client.cc b/content/browser/compositor/onscreen_display_client.cc
index da60316490f034c0e8f530e1a0b713dcca816173..944a187cf6950842b841525ed664a2989057c740 100644
--- a/content/browser/compositor/onscreen_display_client.cc
+++ b/content/browser/compositor/onscreen_display_client.cc
@@ -8,6 +8,7 @@
 #include "cc/output/output_surface.h"
 #include "cc/surfaces/surface_factory.h"
 #include "cc/surfaces/surface_manager.h"
+#include "content/browser/compositor/surface_display_output_surface.h"
 #include "content/common/host_shared_bitmap_manager.h"
 
 namespace content {
@@ -32,6 +33,11 @@ scoped_ptr<cc::OutputSurface> OnscreenDisplayClient::CreateOutputSurface() {
   return output_surface_.Pass();
 }
 
+void OnscreenDisplayClient::CommitVSyncParameters(base::TimeTicks timebase,
+                                                  base::TimeDelta interval) {
+  surface_display_output_surface_->ReceivedVSyncParameters(timebase, interval);

[jamesr, 2014/09/17 05:47:11]

we have an output_surface_ member already, and we know it's always of actual
type SurfaceDisplayOutputSurface, so why not downcast?

or are we just trying to call output_surface_->CommitVSyncParameter()s? if so,
why not do that? because it's protected? making it public seems cleaner than
routing in this roundabout way

+}
+
 void OnscreenDisplayClient::DisplayDamaged() {
   if (scheduled_draw_)
     return;