arc: IPC method to set custom wallpaper.

chrome/browser/chromeos/arc/arc_wallpaper_handler.h

+// 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 CHROME_BROWSER_CHROMEOS_ARC_ARC_WALLPAPER_HANDLER_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_ARC_WALLPAPER_HANDLER_H_
+
+#include "base/macros.h"
+#include "components/arc/set_wallpaper_delegate.h"
+
+namespace arc {
+
+class ArcWallpaperHandler : public SetWallpaperDelegate {
+ public:
+  ArcWallpaperHandler() = default;
+  virtual ~ArcWallpaperHandler() = default;
+
+  // SetWallpaperDelegate implementation.
+  void SetWallpaper(const gfx::ImageSkia& image) override;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ArcWallpaperHandler);
+};
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_WALLPAPER_HANDLER_H_