Add wallpaper experimental api framework and add a simple category list.

chrome/browser/chromeos/extensions/wallpaper_manager_api.h

Index: chrome/browser/chromeos/extensions/wallpaper_manager_api.h
diff --git a/chrome/browser/chromeos/extensions/wallpaper_manager_api.h b/chrome/browser/chromeos/extensions/wallpaper_manager_api.h
new file mode 100644
index 0000000000000000000000000000000000000000..6c4f9474f9e42ee5ffda158786811c1b5ff526f6
--- /dev/null
+++ b/chrome/browser/chromeos/extensions/wallpaper_manager_api.h
@@ -0,0 +1,26 @@
+// 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 CHROME_BROWSER_CHROMEOS_EXTENSIONS_WALLPAPER_MANAGER_API_H_
+#define CHROME_BROWSER_CHROMEOS_EXTENSIONS_WALLPAPER_MANAGER_API_H_
+#pragma once
+
+#include "chrome/browser/extensions/extension_function.h"
+
+// Wallpaper manager strings.
+class WallpaperManagerStringsFunction : public SyncExtensionFunction {
+ public:
+  WallpaperManagerStringsFunction() {}
+
+ protected:
+  virtual ~WallpaperManagerStringsFunction() {}
+
+  // SyncExtensionFunction overrides.
+  virtual bool RunImpl() OVERRIDE;
+
+ private:
+  DECLARE_EXTENSION_FUNCTION_NAME("experimental.wallpaperManager.getStrings");
+};
+
+#endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_WALLPAPER_MANAGER_API_H_