gfx: Add FrameTime and DisplayTime classes

cc/trees/layer_tree_impl.h

Index: cc/trees/layer_tree_impl.h
diff --git a/cc/trees/layer_tree_impl.h b/cc/trees/layer_tree_impl.h
index 76e6d53edb95b7ebacd9335b70a4b4054138a515..ed4684e1eaa504cb3bac33e43690931be5a4467c 100644
--- a/cc/trees/layer_tree_impl.h
+++ b/cc/trees/layer_tree_impl.h
@@ -14,6 +14,7 @@
 #include "cc/layers/layer_impl.h"
 #include "cc/resources/ui_resource_client.h"
 #include "ui/events/latency_info.h"
+#include "ui/gfx/frame_time.h"
 
 #if defined(COMPILER_GCC)
 namespace BASE_HASH_NAMESPACE {
@@ -74,9 +75,9 @@ class CC_EXPORT LayerTreeImpl {
   LayerImpl* FindPendingTreeLayerById(int id);
   int MaxTextureSize() const;
   bool PinchGestureActive() const;
-  base::TimeTicks CurrentFrameTimeTicks() const;
+  gfx::FrameTime CurrentFrameTimeTicks() const;
   base::Time CurrentFrameTime() const;
-  base::TimeTicks CurrentPhysicalTimeTicks() const;
+  gfx::FrameTime CurrentPhysicalFrameTime() const;
   void SetNeedsCommit();
   gfx::Size DrawViewportSize() const;
   void StartScrollbarAnimation();