Revert of Revert of Snap RWHVA and resize the legacy window on Windows whenever the ancestor window's bounds change.

content/browser/renderer_host/render_widget_host_view_aura.h

Index: content/browser/renderer_host/render_widget_host_view_aura.h
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.h b/content/browser/renderer_host/render_widget_host_view_aura.h
index 89bead7ba5d890cf2c78985745ee68f3cef02191..d9e12015d8a94d271dae24baea6215dc985b70da 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.h
+++ b/content/browser/renderer_host/render_widget_host_view_aura.h
@@ -401,6 +401,9 @@
   class WindowObserver;
   friend class WindowObserver;
 
+  class WindowAncestorObserver;
+  friend class WindowAncestorObserver;
+
   void UpdateCursorIfOverSelf();
 
   // Tracks whether SnapToPhysicalPixelBoundary() has been called.
@@ -500,6 +503,12 @@
                               bool mouse_locked,
                               bool selection_popup);
 
+  // Called when the parent window bounds change.
+  void HandleParentBoundsChanged();
+
+  // Called when the parent window hierarchy for our window changes.
+  void ParentHierarchyChanged();
+
   // The model object.
   RenderWidgetHostImpl* host_;
 
@@ -508,6 +517,9 @@
   scoped_ptr<DelegatedFrameHost> delegated_frame_host_;
 
   scoped_ptr<WindowObserver> window_observer_;
+
+  // Tracks the ancestors of the RWHVA window for window location changes.
+  scoped_ptr<WindowAncestorObserver> ancestor_window_observer_;
 
   // Are we in the process of closing?  Tracked so fullscreen views can avoid
   // sending a second shutdown request to the host when they lose the focus