gfx: Add FrameTime and DisplayTime classes

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 52203129e4847b5437ef6559bf254f034eb4f9bb..33bf8df1b86892891e18fa1381f22c43f110cc7b 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -176,7 +176,7 @@ void LayerTreeImpl::SetCurrentlyScrollingLayer(LayerImpl* layer) {
   if (currently_scrolling_layer_ &&
       currently_scrolling_layer_->scrollbar_animation_controller())
     currently_scrolling_layer_->scrollbar_animation_controller()->
-        DidScrollGestureEnd(CurrentPhysicalTimeTicks());
+        DidScrollGestureEnd(CurrentPhysicalFrameTime());
   currently_scrolling_layer_ = layer;
   if (layer && layer->scrollbar_animation_controller())
     layer->scrollbar_animation_controller()->DidScrollGestureBegin();
@@ -577,7 +577,7 @@ bool LayerTreeImpl::PinchGestureActive() const {
   return layer_tree_host_impl_->pinch_gesture_active();
 }
 
-base::TimeTicks LayerTreeImpl::CurrentFrameTimeTicks() const {
+gfx::FrameTime LayerTreeImpl::CurrentFrameTimeTicks() const {
   return layer_tree_host_impl_->CurrentFrameTimeTicks();
 }
 
@@ -585,8 +585,8 @@ base::Time LayerTreeImpl::CurrentFrameTime() const {
   return layer_tree_host_impl_->CurrentFrameTime();
 }
 
-base::TimeTicks LayerTreeImpl::CurrentPhysicalTimeTicks() const {
-  return layer_tree_host_impl_->CurrentPhysicalTimeTicks();
+gfx::FrameTime LayerTreeImpl::CurrentPhysicalFrameTime() const {
+  return layer_tree_host_impl_->CurrentPhysicalFrameTime();
 }
 
 void LayerTreeImpl::SetNeedsCommit() {