cc: Throttle swaps in Scheduler instead of OutputSurface

ui/compositor/compositor.cc

 // 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 "ui/compositor/compositor.h"
 
 #include <algorithm>
 #include <deque>
 
 #include "base/bind.h"
@@ skipping 194 matching lines @@
 
   CommandLine* command_line = CommandLine::ForCurrentProcess();
 
   cc::LayerTreeSettings settings;
   settings.refresh_rate =
       ContextFactory::GetInstance()->DoesCreateTestContexts()
       ? kTestRefreshRate
       : kDefaultRefreshRate;
   settings.main_frame_before_draw_enabled = false;
   settings.main_frame_before_activation_enabled = false;
+  settings.throttle_frame_production =
+      !command_line->HasSwitch(switches::kDisableGpuVsync);

[brianderson, 2014/03/13 21:11:52]

This is needed to get aura-based platforms to honor vsync being disabled,
otherwise the scheduler ticks at the vsync rate instead of ticking when the
swap-ack arrives.

I could move this to a separate patch if needed.

[Sami, 2014/03/14 15:34:58]

+1 for a separate patch so we can more easily tell the rest of this is a no-op.

   settings.partial_swap_enabled =
       !command_line->HasSwitch(cc::switches::kUIDisablePartialSwap);
 #if defined(OS_CHROMEOS)
   settings.per_tile_painting_enabled = true;
 #endif
 
   // These flags should be mirrored by renderer versions in content/renderer/.
   settings.initial_debug_state.show_debug_borders =
       command_line->HasSwitch(cc::switches::kUIShowCompositedLayerBorders);
   settings.initial_debug_state.show_fps_counter =
@@ skipping 334 matching lines @@
     // CompositorObservers to be notified before starting another
     // draw cycle.
     ScheduleDraw();
   }
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingEnded(this));
 }
 
 }  // namespace ui