Proper MouseEvent targeting. Adds a Window method that locates a Window for a given point.

aura/desktop.h

Index: aura/desktop.h
===================================================================
--- aura/desktop.h	(revision 98852)
+++ aura/desktop.h	(working copy)
@@ -6,7 +6,7 @@
 #define AURA_DESKTOP_H_
 #pragma once
 
-#include "aura/window.h"
+#include "aura/root_window.h"
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "ui/gfx/native_widget_types.h"
@@ -23,7 +23,6 @@
 
 class DesktopHost;
 class MouseEvent;
-class Window;
 
 // Desktop is responsible for hosting a set of windows.
 class Desktop {
@@ -31,6 +30,12 @@
   Desktop();
   ~Desktop();
 
+  // Shows the desktop host.
+  void Show();
+
+  // Sets the size of the desktop.
+  void SetSize(const gfx::Size& size);
+
   // Shows the desktop host and runs an event loop for it.
   void Run();
 
@@ -50,7 +55,7 @@
  private:
   scoped_refptr<ui::Compositor> compositor_;
 
-  scoped_ptr<Window> window_;
+  scoped_ptr<internal::RootWindow> window_;
 
   DesktopHost* host_;