Eliminate ash::internal namespace

ash/wm/overlay_event_filter.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 "ash/wm/overlay_event_filter.h"
 
 #include "ash/wm/partial_screenshot_view.h"
 #include "ui/aura/window.h"
 #include "ui/aura/window_delegate.h"
 #include "ui/events/event.h"
 #include "ui/views/widget/widget.h"
 
 namespace ash {
-namespace internal {
 
 OverlayEventFilter::OverlayEventFilter()
     : delegate_(NULL) {
 }
 
 OverlayEventFilter::~OverlayEventFilter() {
   delegate_ = NULL;
 }
 
 void OverlayEventFilter::OnKeyEvent(ui::KeyEvent* event) {
@@ skipping 38 matching lines @@
 }
 
 void OverlayEventFilter::Deactivate() {
   delegate_ = NULL;
 }
 
 void OverlayEventFilter::Cancel() {
   if (delegate_)
     delegate_->Cancel();
 }
-}  // namespace internal
+
 }  // namespace ash