Enable user change background image in settings page in Aura build.

ash/shell.h

 // 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.
 
 #ifndef ASH_SHELL_H_
 #define ASH_SHELL_H_
 #pragma once
 
 #include <utility>
 #include <vector>
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/size.h"
 
 class CommandLine;
+class SkBitmap;
 
 namespace aura {
 class EventFilter;
 class RootWindow;
 class Window;
 }
 namespace gfx {
 class Point;
 class Rect;
 }
 namespace ui {
 class Layer;
 }
 namespace views {
 class NonClientFrameView;
 class Widget;
 }
 
 namespace ash {
 
 class AcceleratorController;
 class AudioController;
 class BrightnessController;
+class DesktopBackgroundController;
 class Launcher;
 class NestedDispatcherController;
 class PowerButtonController;
 class PowerStatusController;
 class ShellDelegate;
 class SystemTrayDelegate;
 class SystemTray;
 class VideoDetector;
 class WindowCycleController;
 
@@ skipping 74 matching lines @@
   void AddRootWindowEventFilter(aura::EventFilter* filter);
   void RemoveRootWindowEventFilter(aura::EventFilter* filter);
   size_t GetRootWindowEventFilterCount() const;
 
   // Shows the background menu over |widget|.
   void ShowBackgroundMenu(views::Widget* widget, const gfx::Point& location);
 
   // Toggles app list.
   void ToggleAppList();
 
-  // Sets the desktop background mode.
-  void SetDesktopBackgroundMode(BackgroundMode mode);
+  // Sets the desktop background wallpaper.

[Ben Goodger (Google), 2012/03/09 23:20:17]

Can we pull all of this off onto a DesktopBackgroundController that the shell
owns, rather than just adding to the shell api

[bshe, 2012/03/12 00:14:25]

Done. I am not sure if you mean to pull the following two functions as well. It
makes sense to me to pull them to DesktopBackgroundController as well, since
they also control background. But I could be wrong. And I am happy to move them
back if I am wrong. Thanks! 

+  void SetDesktopBackgroundWallpaper(const SkBitmap& wallpaper);
+
+  // Sets the desktop background (image mode).
+  void SetDesktopBackgroundImageMode(const SkBitmap& wallpaper);
+
+  // Sets the desktop background (solid color mode).
+  void SetDesktopBackgroundSolidColorMode();
 
   // Returns true if the screen is locked.
   bool IsScreenLocked() const;
 
   // Returns true if a modal dialog window is currently open.
   bool IsModalWindowOpen() const;
 
   // Creates a default views::NonClientFrameView for use by windows in the
   // Ash environment.
   views::NonClientFrameView* CreateDefaultNonClientFrameView(
@@ skipping 10 matching lines @@
 
   internal::RootWindowEventFilter* root_filter() {
     return root_filter_;
   }
   internal::TooltipController* tooltip_controller() {
     return tooltip_controller_.get();
   }
   internal::PartialScreenshotEventFilter* partial_screenshot_filter() {
     return partial_screenshot_filter_.get();
   }
+  DesktopBackgroundController* desktop_background_controller() {
+    return desktop_background_controller_.get();
+  }
   PowerButtonController* power_button_controller() {
     return power_button_controller_.get();
   }
   VideoDetector* video_detector() {
     return video_detector_.get();
   }
   WindowCycleController* window_cycle_controller() {
     return window_cycle_controller_.get();
   }
   internal::FocusCycler* focus_cycler() {
@@ skipping 70 matching lines @@
   scoped_ptr<internal::AppList> app_list_;
 
   scoped_ptr<internal::StackingController> stacking_controller_;
   scoped_ptr<internal::ActivationController> activation_controller_;
   scoped_ptr<internal::WindowModalityController> window_modality_controller_;
   scoped_ptr<internal::DragDropController> drag_drop_controller_;
   scoped_ptr<internal::WorkspaceController> workspace_controller_;
   scoped_ptr<internal::ShadowController> shadow_controller_;
   scoped_ptr<internal::TooltipController> tooltip_controller_;
   scoped_ptr<internal::VisibilityController> visibility_controller_;
+  scoped_ptr<DesktopBackgroundController> desktop_background_controller_;
   scoped_ptr<PowerButtonController> power_button_controller_;
   scoped_ptr<VideoDetector> video_detector_;
   scoped_ptr<WindowCycleController> window_cycle_controller_;
   scoped_ptr<internal::FocusCycler> focus_cycler_;
 
   // These controllers are not owned by the shell.
   AudioController* audio_controller_;
   BrightnessController* brightness_controller_;
   PowerStatusController* power_status_controller_;
 
@@ skipping 26 matching lines @@
   // System tray with clock, Wi-Fi signal, etc. (a replacement in progress for
   // |status_widget_|).
   scoped_ptr<SystemTray> tray_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_