Change LayerHostImpl to use frame time from BeginFrameArgs rather than ::Now()

cc/trees/single_thread_proxy.cc

Index: cc/trees/single_thread_proxy.cc
diff --git a/cc/trees/single_thread_proxy.cc b/cc/trees/single_thread_proxy.cc
index ece908bf4ba38732af71aadd89a4a258fbff5540..ddcb0e301c07191a629d0b6a80c165c43ce19c8d 100644
--- a/cc/trees/single_thread_proxy.cc
+++ b/cc/trees/single_thread_proxy.cc
@@ -532,6 +532,7 @@ bool SingleThreadProxy::DoComposite(
       return false;
     }
 
+    layer_tree_host_impl_->OverrideCurrentFrameTime(frame_begin_time);

[danakj, 2014/03/11 18:32:36]

This is really late, we'll have generated a frame for 1 time, then draw with
another time. I think this should be at the top of CommitAndComposite().

     layer_tree_host_impl_->Animate(
         layer_tree_host_impl_->CurrentFrameTimeTicks());
     UpdateBackgroundAnimateTicking();
@@ -545,8 +546,6 @@ bool SingleThreadProxy::DoComposite(
 
     bool start_ready_animations = true;
     layer_tree_host_impl_->UpdateAnimationState(start_ready_animations);
-
-    layer_tree_host_impl_->ResetCurrentFrameTimeForNextFrame();
   }
 
   if (lost_output_surface) {