gfx: Add FrameTime and DisplayTime classes

ui/compositor/layer_animation_sequence.h

Index: ui/compositor/layer_animation_sequence.h
diff --git a/ui/compositor/layer_animation_sequence.h b/ui/compositor/layer_animation_sequence.h
index 53ce8d6dd40030cf3631cf3bf7863e64557ccef4..2491c9331da01b2d53ccfc4e6872f58a539e9a43 100644
--- a/ui/compositor/layer_animation_sequence.h
+++ b/ui/compositor/layer_animation_sequence.h
@@ -14,6 +14,7 @@
 #include "base/time/time.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/compositor/layer_animation_element.h"
+#include "ui/gfx/frame_time.h"
 
 namespace ui {
 
@@ -44,8 +45,8 @@ class COMPOSITOR_EXPORT LayerAnimationSequence
   // Sets the start time for the animation. This must be called before the
   // first call to {Start, IsFinished}. Once the animation is finished, this
   // must be called again in order to restart the animation.
-  void set_start_time(base::TimeTicks start_time) { start_time_ = start_time; }
-  base::TimeTicks start_time() const { return start_time_; }
+  void set_start_time(gfx::FrameTime start_time) { start_time_ = start_time; }
+  gfx::FrameTime start_time() const { return start_time_; }
 
   // Sets a flag indicating that this sequence will start together with other
   // sequences, and at least one of the sequences in this group has a threaded
@@ -63,11 +64,11 @@ class COMPOSITOR_EXPORT LayerAnimationSequence
 
   // Updates the delegate to the appropriate value for |now|. Requests a
   // redraw if it is required.
-  void Progress(base::TimeTicks now, LayerAnimationDelegate* delegate);
+  void Progress(gfx::FrameTime now, LayerAnimationDelegate* delegate);
 
   // Returns true if calling Progress now, with the given time, will finish
   // the animation.
-  bool IsFinished(base::TimeTicks time);
+  bool IsFinished(gfx::FrameTime time);
 
   // Updates the delegate to the end of the animation; if this sequence is
   // cyclic, updates the delegate to the end of one cycle of the sequence.
@@ -160,10 +161,10 @@ class COMPOSITOR_EXPORT LayerAnimationSequence
 
   // These are used when animating to efficiently find the next element.
   size_t last_element_;
-  base::TimeTicks last_start_;
+  gfx::FrameTime last_start_;
 
   // The start time of the current run of the sequence.
-  base::TimeTicks start_time_;
+  gfx::FrameTime start_time_;
 
   // True if this sequence will start together with other sequences, and at
   // least one of the sequences in this group has a threaded first element.