compositor: Tick the UI animations from cc, instead of from timer callbacks.

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index 7a1b2928a8890ac7d73b46511fa8191782788865..973a7c5e7e5b218255c3eb979c524b4df0b32d26 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -26,6 +26,7 @@
 #include "ui/compositor/compositor_vsync_manager.h"
 #include "ui/compositor/dip_util.h"
 #include "ui/compositor/layer.h"
+#include "ui/compositor/layer_animator_collection.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gl/gl_context.h"
 #include "ui/gl/gl_switches.h"
@@ -317,6 +318,10 @@ bool Compositor::HasObserver(CompositorObserver* observer) {
   return observer_list_.HasObserver(observer);
 }
 
+void Compositor::Animate(base::TimeTicks frame_begin_time) {
+  LayerAnimatorCollection::GetInstance()->Progress(frame_begin_time);
+}
+
 void Compositor::Layout() {
   // We're sending damage that will be addressed during this composite
   // cycle, so we don't need to schedule another composite to address it.
@@ -335,6 +340,8 @@ void Compositor::DidCommit() {
   FOR_EACH_OBSERVER(CompositorObserver,
                     observer_list_,
                     OnCompositingDidCommit(this));
+  if (LayerAnimatorCollection::GetInstance()->HasActiveAnimators())
+    host_->SetNeedsAnimate();

[ajuma, 2014/05/23 17:10:00]

This should be moved to the end of ::Animate above.

[sadrul, 2014/05/23 18:02:42]

Done.

 }
 
 void Compositor::DidCommitAndDrawFrame() {