CC::Animations should use TimeTicks & TimeDelta to represent time

cc/animation/animation_events.cc

Index: cc/animation/animation_events.cc
diff --git a/cc/animation/animation_events.cc b/cc/animation/animation_events.cc
index 95b0e071a21779a29cf3eaad8d6f6ff9bb4213b1..956ae2172d597161b8b9cfebd120cde97e8ca937 100644
--- a/cc/animation/animation_events.cc
+++ b/cc/animation/animation_events.cc
@@ -10,14 +10,13 @@ AnimationEvent::AnimationEvent(AnimationEvent::Type type,
                                int layer_id,
                                int group_id,
                                Animation::TargetProperty target_property,
-                               double monotonic_time)
+                               base::TimeTicks monotonic_time)
     : type(type),
       layer_id(layer_id),
       group_id(group_id),
       target_property(target_property),
       monotonic_time(monotonic_time),
       is_impl_only(false),
-      opacity(0.f) {
-}
+      opacity(0.f) {}
 
 }  // namespace cc