Change system level background from red to black.

ash/wm/workspace/system_background_controller.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/workspace/system_background_controller.h"
 
 #include "ash/shell_window_ids.h"
 #include "ui/aura/root_window.h"
 #include "ui/gfx/canvas.h"
 #include "ui/views/widget/widget.h"
@@ skipping 36 matching lines @@
   controller_ = NULL;
   GetWidget()->Close();
 }
 
 views::View* SystemBackgroundController::View::GetContentsView() {
   return this;
 }
 
 void SystemBackgroundController::View::OnPaint(gfx::Canvas* canvas) {
   // TODO: get image!
-  canvas->DrawColor(SK_ColorRED);
+  canvas->DrawColor(SK_ColorBLACK);
 }
 
 SystemBackgroundController::SystemBackgroundController(aura::RootWindow* root)
     : ALLOW_THIS_IN_INITIALIZER_LIST(view_(new View(this))) {
   views::Widget* widget = new views::Widget;
   views::Widget::InitParams params(
       views::Widget::InitParams::TYPE_WINDOW_FRAMELESS);
   params.delegate = view_;
   params.parent = root->GetChildById(kShellWindowId_SystemBackgroundContainer);
   widget->Init(params);
   widget->SetBounds(params.parent->bounds());
   widget->Show();
   widget->GetNativeView()->SetName("SystemBackground");
 }
 
 SystemBackgroundController::~SystemBackgroundController() {
   if (view_)
     view_->Close();
 }
 
 }  // namespace internal
 }  // namespace ash