Set BrowserCompositorOutputSurface's vsync parameters on mac

content/browser/renderer_host/browser_compositor_view_mac.mm

 // Copyright 2014 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/browser_compositor_view_mac.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 270 matching lines @@
     recyclable_compositor_->compositor()->SetDisplayColorSpace(color_space);
 }
 
 void BrowserCompositorMac::UpdateVSyncParameters(
     const base::TimeTicks& timebase,
     const base::TimeDelta& interval) {
   if (recyclable_compositor_) {
     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).

 }
 
 void BrowserCompositorMac::SetRenderWidgetHostIsHidden(bool hidden) {
   render_widget_host_is_hidden_ = hidden;
   UpdateState();
 }
 
 void BrowserCompositorMac::SetNSViewAttachedToWindow(bool attached) {
   ns_view_attached_to_window_ = attached;
   UpdateState();
@@ skipping 160 matching lines @@
 
 const cc::BeginFrameArgs& BrowserCompositorMac::LastUsedBeginFrameArgs() const {
   return last_begin_frame_args_;
 }
 
 void BrowserCompositorMac::OnBeginFrameSourcePausedChanged(bool paused) {
   // Only used on Android WebView.
 }
 
 }  // namespace content