cc: Use HighResNow as timebase if it is fast and reliable

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/debug/test_context_provider.h"
 #include "cc/debug/test_web_graphics_context_3d.h"
 #include "cc/output/managed_memory_policy.h"
 #include "cc/output/output_surface_client.h"
 #include "cc/output/software_output_device.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/fake_output_surface_client.h"
 #include "cc/test/scheduler_test_common.h"
 #include "gpu/GLES2/gl2extchromium.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/frame_time.h"
 
 namespace cc {
 namespace {
 
 class TestOutputSurface : public OutputSurface {
  public:
   explicit TestOutputSurface(scoped_refptr<ContextProvider> context_provider)
       : OutputSurface(context_provider),
         retroactive_begin_frame_deadline_enabled_(false),
         override_retroactive_period_(false) {}
@@ skipping 347 matching lines @@
   const base::TimeDelta display_refresh_interval = big_interval;
 
   output_surface.InitializeBeginFrameEmulation(
       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(
-      base::TimeTicks::Now() - base::TimeDelta::FromSeconds(1), big_interval);
+      gfx::FrameTime::Now() - base::TimeDelta::FromSeconds(1), big_interval);
 
   output_surface.SetMaxFramesPending(2);
   output_surface.EnableRetroactiveBeginFrameDeadline(true, true, big_interval);
 
   // We should start off with 0 BeginFrames
   EXPECT_EQ(client.begin_frame_count(), 0);
   EXPECT_EQ(output_surface.pending_swap_buffers(), 0);
 
   // The first SetNeedsBeginFrame(true) should start a retroactive BeginFrame.
   EXPECT_FALSE(task_runner->HasPendingTask());
@@ skipping 81 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