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

If base::TimeTicks::HighResNow is fast and reliable, we use it
for frame times, animations, and scheduling. Otherwise, we use
base::TimeTicks::Now and use a timebase of zero to avoid an
incorrect or jittery timebase.

This adds a gfx::FrameTime::Now() function, so the same timebase
is used across the ui and cc directories.

Additionally, the OutputSurface now uses a HighRes version of the
DelayBasedTimesource if gfx::FrameTime::Now() is HighRes.

BUG=303356

Review URL: https://codereview.chromium.org/27710005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231089 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 10 insertions, 8 deletions

diff --git a/cc/input/top_controls_manager.cc b/cc/input/top_controls_manager.cc
index 1d1b1a2..871d9e6 100644
--- a/cc/input/top_controls_manager.cc
+++ b/cc/input/top_controls_manager.cc
@@ -7,11 +7,12 @@
 #include <algorithm>
 
 #include "base/logging.h"
-#include "base/time/time.h"
 #include "cc/animation/keyframed_animation_curve.h"
 #include "cc/animation/timing_function.h"
 #include "cc/input/top_controls_manager_client.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/trees/layer_tree_impl.h"
+#include "ui/gfx/frame_time.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/vector2d_f.h"
 
@@ -194,7 +195,7 @@ void TopControlsManager::SetupAnimation(AnimationDirection direction) {
 
   top_controls_animation_ = KeyframedFloatAnimationCurve::Create();
   double start_time =
-      (base::TimeTicks::Now() - base::TimeTicks()).InMillisecondsF();
+      (gfx::FrameTime::Now() - base::TimeTicks()).InMillisecondsF();
   top_controls_animation_->AddKeyframe(
       FloatKeyframe::Create(start_time, controls_top_offset_,
                             scoped_ptr<TimingFunction>()));
diff --git a/cc/input/top_controls_manager_unittest.cc b/cc/input/top_controls_manager_unittest.cc
index 799f018..74687ad 100644
--- a/cc/input/top_controls_manager_unittest.cc
+++ b/cc/input/top_controls_manager_unittest.cc
@@ -12,6 +12,7 @@
 #include "cc/test/fake_layer_tree_host_impl.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "testing/gtest/include/gtest/gtest.h"
+#include "ui/gfx/frame_time.h"
 #include "ui/gfx/vector2d_f.h"
 
 namespace cc {
@@ -131,7 +132,7 @@ TEST(TopControlsManagerTest, PartialShownHideAnimation) {
 
   EXPECT_TRUE(manager->animation());
 
-  base::TimeTicks time = base::TimeTicks::Now();
+  base::TimeTicks time = gfx::FrameTime::Now();
   float previous_offset = manager->controls_top_offset();
   while (manager->animation()) {
     time = base::TimeDelta::FromMicroseconds(100) + time;
@@ -161,7 +162,7 @@ TEST(TopControlsManagerTest, PartialShownShowAnimation) {
 
   EXPECT_TRUE(manager->animation());
 
-  base::TimeTicks time = base::TimeTicks::Now();
+  base::TimeTicks time = gfx::FrameTime::Now();
   float previous_offset = manager->controls_top_offset();
   while (manager->animation()) {
     time = base::TimeDelta::FromMicroseconds(100) + time;
@@ -187,7 +188,7 @@ TEST(TopControlsManagerTest, PartialHiddenWithAmbiguousThresholdShows) {
   manager->ScrollEnd();
   EXPECT_TRUE(manager->animation());
 
-  base::TimeTicks time = base::TimeTicks::Now();
+  base::TimeTicks time = gfx::FrameTime::Now();
   float previous_offset = manager->controls_top_offset();
   while (manager->animation()) {
     time = base::TimeDelta::FromMicroseconds(100) + time;
@@ -213,7 +214,7 @@ TEST(TopControlsManagerTest, PartialHiddenWithAmbiguousThresholdHides) {
   manager->ScrollEnd();
   EXPECT_TRUE(manager->animation());
 
-  base::TimeTicks time = base::TimeTicks::Now();
+  base::TimeTicks time = gfx::FrameTime::Now();
   float previous_offset = manager->controls_top_offset();
   while (manager->animation()) {
     time = base::TimeDelta::FromMicroseconds(100) + time;
@@ -243,7 +244,7 @@ TEST(TopControlsManagerTest, PartialShownWithAmbiguousThresholdHides) {
   manager->ScrollEnd();
   EXPECT_TRUE(manager->animation());
 
-  base::TimeTicks time = base::TimeTicks::Now();
+  base::TimeTicks time = gfx::FrameTime::Now();
   float previous_offset = manager->controls_top_offset();
   while (manager->animation()) {
     time = base::TimeDelta::FromMicroseconds(100) + time;
@@ -273,7 +274,7 @@ TEST(TopControlsManagerTest, PartialShownWithAmbiguousThresholdShows) {
   manager->ScrollEnd();
   EXPECT_TRUE(manager->animation());
 
-  base::TimeTicks time = base::TimeTicks::Now();
+  base::TimeTicks time = gfx::FrameTime::Now();
   float previous_offset = manager->controls_top_offset();
   while (manager->animation()) {
     time = base::TimeDelta::FromMicroseconds(100) + time;