[ash-md] Updated the overflow shelf to change colors based on the wallpaper.

ash/shelf/shelf_widget.cc

 // Copyright 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/shelf/shelf_widget.h"
 
 #include "ash/animation/animation_change_type.h"
 #include "ash/focus_cycler.h"
 #include "ash/public/cpp/window_properties.h"
 #include "ash/root_window_controller.h"
@@ skipping 66 matching lines @@
 };
 
 ShelfWidget::DelegateView::DelegateView(ShelfWidget* shelf_widget)
     : shelf_widget_(shelf_widget),
       focus_cycler_(nullptr),
       opaque_background_(ui::LAYER_SOLID_COLOR),
       opaque_foreground_(ui::LAYER_SOLID_COLOR) {
   DCHECK(shelf_widget_);
   SetLayoutManager(new views::FillLayout());
   set_allow_deactivate_on_esc(true);
-  opaque_background_.SetColor(SK_ColorBLACK);
   opaque_background_.SetBounds(GetLocalBounds());
-  opaque_foreground_.SetColor(SK_ColorBLACK);
   opaque_foreground_.SetBounds(GetLocalBounds());
   opaque_foreground_.SetOpacity(0.0f);
 }
 
 ShelfWidget::DelegateView::~DelegateView() {}
 
 void ShelfWidget::DelegateView::SetParentLayer(ui::Layer* layer) {
   layer->Add(&opaque_background_);
   layer->Add(&opaque_foreground_);
   ReorderLayers();
@@ skipping 246 matching lines @@
   if (shelf_view_)
     shelf_view_->UpdateShelfItemBackground(color);
 }
 
 void ShelfWidget::WillDeleteShelfLayoutManager() {
   shelf_layout_manager_->RemoveObserver(this);
   shelf_layout_manager_ = nullptr;
 }
 
 }  // namespace ash