Propagate window transformed notification to child hierarchy

ui/aura/window_observer.h

Index: ui/aura/window_observer.h
diff --git a/ui/aura/window_observer.h b/ui/aura/window_observer.h
index 9aaeca8f9578f5ef79ee651c7d256676ebf1a692..38e4170abd05a644f6aed1045f48dc0928e9eea9 100644
--- a/ui/aura/window_observer.h
+++ b/ui/aura/window_observer.h
@@ -82,6 +82,11 @@ class AURA_EXPORT WindowObserver {
   virtual void OnWindowTransforming(Window* window) {}
   virtual void OnWindowTransformed(Window* window) {}
 
+  // Invoked when SetTransform() is invoked on an |ancestor| of the |window|
+  // being observed. Note that this will also be invoked on the |ancestor|
+  // observers.
+  virtual void OnAncestorWindowTransformed(Window* window, Window* ancestor) {}

[sky, 2014/09/10 15:13:27]

Can you swap the order of these and rename ancestor to source?

[mohsen, 2014/09/10 15:48:59]

Done.

+
   // Invoked when |window|'s position among its siblings in the stacking order
   // has changed.
   virtual void OnWindowStackingChanged(Window* window) {}