views: Extract Widget observer into its own header file.

chrome/browser/ui/panels/panel_view.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 "chrome/browser/ui/panels/panel_view.h"
 
 #include "base/logging.h"
 #include "chrome/browser/ui/panels/panel.h"
 #include "chrome/browser/ui/panels/panel_bounds_animation.h"
 #include "chrome/browser/ui/panels/panel_frame_view.h"
 #include "chrome/browser/ui/panels/panel_manager.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/render_widget_host_view.h"
 #include "ui/gfx/path.h"
 #include "ui/gfx/screen.h"
 #include "ui/views/controls/button/image_button.h"
 #include "ui/views/controls/webview/webview.h"
+#include "ui/views/widget/widget.h"
 
 #if defined(OS_WIN) && !defined(USE_ASH) && !defined(USE_AURA)
 #include "base/win/windows_version.h"
 #include "chrome/browser/ui/panels/taskbar_window_thumbnailer_win.h"
 #endif
 
 namespace {
 
 // NativePanelTesting implementation.
 class NativePanelTestingWin : public NativePanelTesting {
@@ skipping 649 matching lines @@
   int height = web_view_->size().height();
   SkRegion* region = new SkRegion;
   region->op(0, 0, kResizeInsideBoundsSize, height, SkRegion::kUnion_Op);
   region->op(width - kResizeInsideBoundsSize, 0, width, height,
       SkRegion::kUnion_Op);
   region->op(0, height - kResizeInsideBoundsSize, width, height,
       SkRegion::kUnion_Op);
   web_contents->GetRenderViewHost()->GetView()->SetClickthroughRegion(region);
 #endif
 }