Refactor ClipboardRecentContent singleton creation.

ios/chrome/browser/open_from_clipboard/create_clipboard_recent_content.h

+// Copyright 2015 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 IOS_CHROME_BROWSER_OPEN_FROM_CLIPBOARD_CREATE_CLIPBOARD_RECENT_CONTENT_H_
+#define IOS_CHROME_BROWSER_OPEN_FROM_CLIPBOARD_CREATE_CLIPBOARD_RECENT_CONTENT_H_
+
+#include "base/memory/scoped_ptr.h"
+
+class ClipboardRecentContent;
+
+// Creates a new instance of ClipboardRecentContentIOS. The returned object
+// is fully initialized and can be registered as global singleton.
+//
+// This helper function allow the construction of ClipboardRecentContentIOS
+// from a pure C++ (ClipboardRecentContentIOS is an Objective-C++).
+scoped_ptr<ClipboardRecentContent> CreateClipboadRecentContentIOS();
+
+#endif  // IOS_CHROME_BROWSER_OPEN_FROM_CLIPBOARD_CREATE_CLIPBOARD_RECENT_CONTENT_H_