Replace Ash web notification tray view with a button.

ash/system/tray/tray_background_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 "ash/system/tray/tray_background_view.h"
 
 #include "ash/launcher/background_animator.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/status_area_widget.h"
@@ skipping 134 matching lines @@
     layout->set_spread_blank_space(true);
     views::View::SetLayoutManager(layout);
   }
   PreferredSizeChanged();
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // TrayBackgroundView
 
 TrayBackgroundView::TrayBackgroundView(
-    internal::StatusAreaWidget* status_area_widget)
+    internal::StatusAreaWidget* status_area_widget,
+    bool set_background)
     : status_area_widget_(status_area_widget),
       tray_container_(NULL),
       shelf_alignment_(SHELF_ALIGNMENT_BOTTOM),
       background_(NULL),
       ALLOW_THIS_IN_INITIALIZER_LIST(hide_background_animator_(
           this, 0, kTrayBackgroundAlpha)),
       ALLOW_THIS_IN_INITIALIZER_LIST(hover_background_animator_(
           this, 0, kTrayBackgroundHoverAlpha - kTrayBackgroundAlpha)),
       ALLOW_THIS_IN_INITIALIZER_LIST(layer_animation_observer_(
           new TrayLayerAnimationObserver(this))) {
   set_notify_enter_exit_on_child(true);
 
   // Initially we want to paint the background, but without the hover effect.
   SetPaintsBackground(true, internal::BackgroundAnimator::CHANGE_IMMEDIATE);
   hover_background_animator_.SetPaintsBackground(false,
       internal::BackgroundAnimator::CHANGE_IMMEDIATE);
 
   tray_container_ = new TrayContainer(shelf_alignment_);
-  SetContents(tray_container_);
+  SetContents(tray_container_, set_background);
 }
 
 TrayBackgroundView::~TrayBackgroundView() {
   if (GetWidget()) {
     GetWidget()->GetNativeView()->layer()->GetAnimator()->RemoveObserver(
         layer_animation_observer_.get());
   }
 }
 
 void TrayBackgroundView::Initialize() {
@@ skipping 43 matching lines @@
 }
 
 void TrayBackgroundView::UpdateBackground(int alpha) {
   if (background_) {
     background_->set_alpha(hide_background_animator_.alpha() +
                            hover_background_animator_.alpha());
   }
   SchedulePaint();
 }
 
-void TrayBackgroundView::SetContents(views::View* contents) {
-  background_ = new internal::TrayBackground;
-  contents->set_background(background_);
+void TrayBackgroundView::SetContents(views::View* contents,
+                                     bool set_background) {
+  if (set_background) {
+    background_ = new internal::TrayBackground;
+    contents->set_background(background_);
+  }
 
   SetLayoutManager(new views::BoxLayout(views::BoxLayout::kVertical, 0, 0, 0));
   AddChildView(contents);
 }
 
 void TrayBackgroundView::SetPaintsBackground(
       bool value,
       internal::BackgroundAnimator::ChangeType change_type) {
   hide_background_animator_.SetPaintsBackground(value, change_type);
 }
@@ skipping 25 matching lines @@
         kPaddingFromOuterEdgeOfLauncherVerticalAlignment));
   }
 }
 
 void TrayBackgroundView::UpdateShouldShowLauncher() {
   status_area_widget()->UpdateShouldShowLauncher();
 }
 
 }  // namespace internal
 }  // namespace ash