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

cc/output/begin_frame_args.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/begin_frame_args.h"
+#include "ui/gfx/frame_time.h"
 
 namespace cc {
 
 BeginFrameArgs::BeginFrameArgs()
   : frame_time(base::TimeTicks()),
     deadline(base::TimeTicks()),
     interval(base::TimeDelta::FromMicroseconds(-1)) {
 }
 
 BeginFrameArgs::BeginFrameArgs(base::TimeTicks frame_time,
                                base::TimeTicks deadline,
                                base::TimeDelta interval)
   : frame_time(frame_time),
     deadline(deadline),
     interval(interval)
 {}
 
 BeginFrameArgs BeginFrameArgs::Create(base::TimeTicks frame_time,
                                       base::TimeTicks deadline,
                                       base::TimeDelta interval) {
   return BeginFrameArgs(frame_time, deadline, interval);
 }
 
 BeginFrameArgs BeginFrameArgs::CreateForSynchronousCompositor() {
   // For WebView/SynchronousCompositor, we always want to draw immediately,
   // so we set the deadline to 0 and guess that the interval is 16 milliseconds.
-  return BeginFrameArgs(base::TimeTicks::Now(),
+  return BeginFrameArgs(gfx::FrameTime::Now(),
                         base::TimeTicks(),
                         DefaultInterval());
 }
 
 BeginFrameArgs BeginFrameArgs::CreateForTesting() {
-  base::TimeTicks now = base::TimeTicks::Now();
+  base::TimeTicks now = gfx::FrameTime::Now();
   return BeginFrameArgs(now,
                         now + (DefaultInterval() / 2),
                         DefaultInterval());
 }
 
 BeginFrameArgs BeginFrameArgs::CreateExpiredForTesting() {
-  base::TimeTicks now = base::TimeTicks::Now();
+  base::TimeTicks now = gfx::FrameTime::Now();
   return BeginFrameArgs(now,
                         now - DefaultInterval(),
                         DefaultInterval());
 }
 
 // This is a hard-coded deadline adjustment that assumes 60Hz, to be used in
 // cases where a good estimated draw time is not known. Using 1/3 of the vsync
 // as the default adjustment gives the Browser the last 1/3 of a frame to
 // produce output, the Renderer Impl thread the middle 1/3 of a frame to produce
 // ouput, and the Renderer Main thread the first 1/3 of a frame to produce
 // output.
 base::TimeDelta BeginFrameArgs::DefaultDeadlineAdjustment() {
   return base::TimeDelta::FromMicroseconds(-16666 / 3);
 }
 
 base::TimeDelta BeginFrameArgs::DefaultInterval() {
   return base::TimeDelta::FromMicroseconds(16666);
 }
 
 base::TimeDelta BeginFrameArgs::DefaultRetroactiveBeginFramePeriod() {
   return base::TimeDelta::FromMicroseconds(4444);
 }
 
 }  // namespace cc