Get event targetting working for mouse events.

ui/aura/window.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/aura/window.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 1397 matching lines @@
 
 ui::EventTarget* Window::GetParentTarget() {
   if (IsRootWindow()) {
     return client::GetEventClient(this) ?
         client::GetEventClient(this)->GetToplevelEventTarget() :
             Env::GetInstance();
   }
   return parent_;
 }
 
-scoped_ptr<ui::EventTargetIterator> Window::GetChildIterator() const {
+scoped_ptr<ui::EventTargetIterator> Window::GetChildIterator() {
   return scoped_ptr<ui::EventTargetIterator>(
       new ui::EventTargetIteratorImpl<Window>(children()));
 }
 
 ui::EventTargeter* Window::GetEventTargeter() {
   return targeter_.get();
 }
 
 void Window::ConvertEventToTarget(ui::EventTarget* target,
                                   ui::LocatedEvent* event) {
@@ skipping 32 matching lines @@
       return window;
     if (offset)
       *offset += window->bounds().OffsetFromOrigin();
   }
   if (offset)
     *offset = gfx::Vector2d();
   return NULL;
 }
 
 }  // namespace aura