Enable BeginFrame scheduling on aura

content/browser/renderer_host/render_widget_host_view_mac.mm

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 422 matching lines @@
     int output_surface_id,
     const cc::CompositorFrameAck& ack) {
   render_widget_host_->Send(new ViewMsg_ReclaimCompositorResources(
       render_widget_host_->GetRoutingID(), output_surface_id, ack));
 }
 
 void RenderWidgetHostViewMac::DelegatedFrameHostOnLostCompositorResources() {
   render_widget_host_->ScheduleComposite();
 }
 
-void RenderWidgetHostViewMac::DelegatedFrameHostUpdateVSyncParameters(

[danakj, 2015/03/25 17:40:38]

So what's the expected outcome on Mac for this patch?

[simonhong, 2015/03/25 18:05:22]

So far, this function was never called because Mac doesn't get vsync from gpu.
So, we can delete this.

-    const base::TimeTicks& timebase,
-    const base::TimeDelta& interval) {
-  render_widget_host_->UpdateVSyncParameters(timebase, interval);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // AcceleratedWidgetMacNSView, public:
 
 NSView* RenderWidgetHostViewMac::AcceleratedWidgetGetNSView() const {
   return cocoa_view_;
 }
 
 bool RenderWidgetHostViewMac::AcceleratedWidgetShouldIgnoreBackpressure()
     const {
   // If vsync is disabled, then always draw and ack frames immediately.
@@ skipping 2990 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end