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

cc/trees/thread_proxy.cc

 // Copyright 2011 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/trees/thread_proxy.h"
 
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/metrics/histogram.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/input/input_handler.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/resources/prioritized_resource_manager.h"
 #include "cc/scheduler/delay_based_time_source.h"
 #include "cc/scheduler/frame_rate_controller.h"
 #include "cc/scheduler/scheduler.h"
 #include "cc/trees/blocking_task_runner.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
+#include "ui/gfx/frame_time.h"
 
 // Measured in seconds.
 const double kSmoothnessTakesPriorityExpirationDelay = 0.25;
 
 const size_t kDurationHistorySize = 60;
 const double kCommitAndActivationDurationEstimationPercentile = 50.0;
 const double kDrawDurationEstimationPercentile = 100.0;
 const int kDrawDurationEstimatePaddingInMicroseconds = 0;
 
 namespace cc {
@@ skipping 1213 matching lines @@
       kCommitAndActivationDurationEstimationPercentile);
 }
 
 base::TimeDelta ThreadProxy::CommitToActivateDurationEstimate() {
   return commit_to_activate_duration_history_.Percentile(
       kCommitAndActivationDurationEstimationPercentile);
 }
 
 void ThreadProxy::PostBeginImplFrameDeadline(const base::Closure& closure,
                                              base::TimeTicks deadline) {
-  base::TimeDelta delta = deadline - base::TimeTicks::Now();
+  base::TimeDelta delta = deadline - gfx::FrameTime::Now();
   if (delta <= base::TimeDelta())
     delta = base::TimeDelta();
   Proxy::ImplThreadTaskRunner()->PostDelayedTask(FROM_HERE, closure, delta);
 }
 
 void ThreadProxy::DidBeginImplFrameDeadline() {
   layer_tree_host_impl_->ResetCurrentFrameTimeForNextFrame();
 }
 
 void ThreadProxy::ReadyToFinalizeTextureUpdates() {
@@ skipping 315 matching lines @@
     completion_event_for_commit_held_on_tree_activation_ = NULL;
   }
 
   UpdateBackgroundAnimateTicking();
 
   commit_to_activate_duration_history_.InsertSample(
       base::TimeTicks::HighResNow() - commit_complete_time_);
 }
 
 }  // namespace cc