gfx: Add FrameTime and DisplayTime classes

ui/gfx/animation/animation_container_element.h

Index: ui/gfx/animation/animation_container_element.h
diff --git a/ui/gfx/animation/animation_container_element.h b/ui/gfx/animation/animation_container_element.h
index 224655eb31804700d90c2b8f0d56d5fd3e6aaaa8..4136ae9c313f45a40a567f0d2722735f3d9fe965 100644
--- a/ui/gfx/animation/animation_container_element.h
+++ b/ui/gfx/animation/animation_container_element.h
@@ -7,6 +7,7 @@
 
 #include "base/time/time.h"
 #include "ui/gfx/gfx_export.h"
+#include "ui/gfx/frame_time.h"
 
 namespace gfx {
 
@@ -16,10 +17,10 @@ class GFX_EXPORT AnimationContainerElement {
  public:
   // Sets the start of the animation. This is invoked from
   // AnimationContainer::Start.
-  virtual void SetStartTime(base::TimeTicks start_time) = 0;
+  virtual void SetStartTime(gfx::FrameTime start_time) = 0;
 
   // Invoked when the animation is to progress.
-  virtual void Step(base::TimeTicks time_now) = 0;
+  virtual void Step(gfx::FrameTime time_now) = 0;
 
   // Returns the time interval of the animation. If an Element needs to change
   // this it should first invoke Stop, then Start.