views: Extract Widget observer into its own header file.

chrome/browser/ui/views/browser_actions_container.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/views/browser_actions_container.h"
 
 #include "base/stl_util.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 12 matching lines @@
 #include "grit/ui_resources.h"
 #include "ui/base/accessibility/accessible_view_state.h"
 #include "ui/base/animation/slide_animation.h"
 #include "ui/base/dragdrop/drag_utils.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/theme_provider.h"
 #include "ui/gfx/canvas.h"
 #include "ui/views/controls/resize_area.h"
 #include "ui/views/metrics.h"
+#include "ui/views/widget/widget.h"
 
 using extensions::Extension;
 
 namespace {
 
 // Horizontal spacing between most items in the container, as well as after the
 // last item or chevron (if visible).
 const int kItemSpacing = ToolbarView::kStandardSpacing;
 
 // Horizontal spacing before the chevron (if visible).
@@ skipping 763 matching lines @@
   views::BubbleBorder::ArrowLocation arrow_location = base::i18n::IsRTL() ?
       views::BubbleBorder::TOP_LEFT : views::BubbleBorder::TOP_RIGHT;
   popup_ = ExtensionPopup::ShowPopup(popup_url,
                                      browser_,
                                      reference_view,
                                      arrow_location);
   popup_->GetWidget()->AddObserver(this);
   popup_button_ = button;
   popup_button_->SetButtonPushed();
 }