Set BrowserCompositorOutputSurface's vsync parameters on mac

content/browser/renderer_host/browser_compositor_view_mac.mm

Index: content/browser/renderer_host/browser_compositor_view_mac.mm
diff --git a/content/browser/renderer_host/browser_compositor_view_mac.mm b/content/browser/renderer_host/browser_compositor_view_mac.mm
index 58d2a2ff368bda50738bfc8682458caf71c4e603..c63ee6e4219af3f1424d11229f4d5317eb8ed8f1 100644
--- a/content/browser/renderer_host/browser_compositor_view_mac.mm
+++ b/content/browser/renderer_host/browser_compositor_view_mac.mm
@@ -288,6 +288,10 @@ void BrowserCompositorMac::UpdateVSyncParameters(
     recyclable_compositor_->compositor()
         ->vsync_manager()
         ->UpdateVSyncParameters(timebase, interval);
+    recyclable_compositor_->compositor()
+        ->context_factory()
+        ->SetDisplayVSyncParameters(recyclable_compositor_->compositor(),
+                                    timebase, interval);
   }

[ccameron, 2016/07/25 17:30:12]

Would it make sense to just do:
    if (begin_frame_source_)
      begin_frame_source_->OnUpdateVSyncParameters(timebase, interval);
Or is |begin_frame_source_| in this context different than in GPTF?

This gets called at every swap (the arguments only change every few seconds, so
if too-frequent-calls is a problem, we can elide redundant ones here).

 }