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

cc/output/output_surface.cc

Index: cc/output/output_surface.cc
diff --git a/cc/output/output_surface.cc b/cc/output/output_surface.cc
index bcebeab429013bc938520fba4cee90133ac829df..a8f865cb424541cc967b91fbbf6c6e1d2c2d2733 100644
--- a/cc/output/output_surface.cc
+++ b/cc/output/output_surface.cc
@@ -25,6 +25,7 @@
 #include "third_party/WebKit/public/platform/WebGraphicsContext3D.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "third_party/khronos/GLES2/gl2ext.h"
+#include "ui/gfx/frame_time.h"
 #include "ui/gfx/rect.h"
 #include "ui/gfx/size.h"
 
@@ -95,9 +96,12 @@ void OutputSurface::InitializeBeginFrameEmulation(
     bool throttle_frame_production,
     base::TimeDelta interval) {
   if (throttle_frame_production) {
-    frame_rate_controller_.reset(
-        new FrameRateController(
-            DelayBasedTimeSource::Create(interval, task_runner)));
+    scoped_refptr<DelayBasedTimeSource> time_source;
+    if (gfx::FrameTime::TimestampsAreHighRes())
+      time_source = DelayBasedTimeSourceHighRes::Create(interval, task_runner);
+    else
+      time_source = DelayBasedTimeSource::Create(interval, task_runner);
+    frame_rate_controller_.reset(new FrameRateController(time_source));
   } else {
     frame_rate_controller_.reset(new FrameRateController(task_runner));
   }
@@ -198,7 +202,7 @@ void OutputSurface::PostCheckForRetroactiveBeginFrame() {
 void OutputSurface::CheckForRetroactiveBeginFrame() {
   TRACE_EVENT0("cc", "OutputSurface::CheckForRetroactiveBeginFrame");
   check_for_retroactive_begin_frame_pending_ = false;
-  if (base::TimeTicks::Now() < RetroactiveBeginFrameDeadline())
+  if (gfx::FrameTime::Now() < RetroactiveBeginFrameDeadline())
     BeginFrame(skipped_begin_frame_args_);
 }