Read compositor VSync information from platform, when possible

cc/output/output_surface_unittest.cc

 // Copyright 2013 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 "cc/output/output_surface.h"
 
 #include "base/test/test_simple_task_runner.h"
 #include "cc/output/managed_memory_policy.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/output/software_output_device.h"
@@ skipping 28 matching lines @@
         override_retroactive_period_(false) {}
 
   bool InitializeNewContext3d(
       scoped_refptr<ContextProvider> new_context_provider) {
     return InitializeAndSetContext3d(new_context_provider,
                                      scoped_refptr<ContextProvider>());
   }
 
   using OutputSurface::ReleaseGL;
 
-  void OnVSyncParametersChangedForTesting(base::TimeTicks timebase,
-                                          base::TimeDelta interval) {
-    OnVSyncParametersChanged(timebase, interval);
+  void CommitVSyncParametersForTesting(base::TimeTicks timebase,
+                                       base::TimeDelta interval) {
+    CommitVSyncParameters(timebase, interval);
   }
 
   void BeginImplFrameForTesting() {
     OutputSurface::BeginImplFrame(BeginFrameArgs::CreateExpiredForTesting());
   }
 
   void DidSwapBuffersForTesting() {
     DidSwapBuffers();
   }
 
@@ skipping 318 matching lines @@
   bool throttle_frame_production = true;
   const base::TimeDelta display_refresh_interval = big_interval;
 
   output_surface.InitializeBeginImplFrameEmulation(
       task_runner.get(),
       throttle_frame_production,
       display_refresh_interval);
 
   // We need to subtract an epsilon from Now() because some platforms have
   // a slow clock.
-  output_surface.OnVSyncParametersChangedForTesting(
+  output_surface.CommitVSyncParametersForTesting(
       gfx::FrameTime::Now() - base::TimeDelta::FromSeconds(1), big_interval);
 
   output_surface.SetMaxFramesPending(2);
   output_surface.EnableRetroactiveBeginImplFrameDeadline(
       true, true, big_interval);
 
   // We should start off with 0 BeginImplFrames
   EXPECT_EQ(client.begin_impl_frame_count(), 0);
   EXPECT_EQ(output_surface.pending_swap_buffers(), 0);
 
@@ skipping 64 matching lines @@
   EXPECT_EQ(1, software_output_device->ensure_backbuffer_count());
   EXPECT_EQ(0, software_output_device->discard_backbuffer_count());
   output_surface.DiscardBackbuffer();
 
   EXPECT_EQ(1, software_output_device->ensure_backbuffer_count());
   EXPECT_EQ(1, software_output_device->discard_backbuffer_count());
 }
 
 }  // namespace
 }  // namespace cc