Hook up Chrome's wallpaper picker for mash.

ash/mus/user_wallpaper_delegate_mus.h

-// Copyright 2013 The Chromium Authors. All rights reserved.
+// Copyright 2016 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_DEFAULT_USER_WALLPAPER_DELEGATE_H_
-#define ASH_DEFAULT_USER_WALLPAPER_DELEGATE_H_
+#ifndef ASH_USER_WALLPAPER_DELEGATE_MUS_H_
+#define ASH_USER_WALLPAPER_DELEGATE_MUS_H_
 
 #include "ash/ash_export.h"
 #include "ash/desktop_background/user_wallpaper_delegate.h"
-#include "base/compiler_specific.h"
 #include "base/macros.h"
+#include "mash/public/interfaces/wallpaper.mojom.h"
 
 namespace ash {
 
-class ASH_EXPORT DefaultUserWallpaperDelegate : public UserWallpaperDelegate {
+class ASH_EXPORT UserWallpaperDelegateMus
+    : public UserWallpaperDelegate,
+      public mash::mojom::WallpaperController {
  public:
-  DefaultUserWallpaperDelegate() {}
-  ~DefaultUserWallpaperDelegate() override {}
+  UserWallpaperDelegateMus();
+  ~UserWallpaperDelegateMus() override;
 
+ private:
   // UserWallpaperDelegate overrides:
   int GetAnimationType() override;
   int GetAnimationDurationOverride() override;
   void SetAnimationDurationOverride(int animation_duration_in_ms) override;
   bool ShouldShowInitialAnimation() override;
   void UpdateWallpaper(bool clear_cache) override;
   void InitializeWallpaper() override;
   void OpenSetWallpaperPage() override;
   bool CanOpenSetWallpaperPage() override;
   void OnWallpaperAnimationFinished() override;
   void OnWallpaperBootAnimationFinished() override;
 
- private:
-  DISALLOW_COPY_AND_ASSIGN(DefaultUserWallpaperDelegate);
+  // mash::mojom::WallpaperController overrides:
+  void SetWallpaper(skia::mojom::BitmapPtr wallpaper, int32_t layout) override;
+
+  DISALLOW_COPY_AND_ASSIGN(UserWallpaperDelegateMus);
 };
 
 }  // namespace ash
 
-#endif  // ASH_DEFAULT_USER_WALLPAPER_DELEGATE_H_
+#endif  // ASH_USER_WALLPAPER_DELEGATE_MUS_H_