Make the id used in IconMsg_DownloadFavicon unique

chrome/browser/favicon/favicon_util.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 CHROME_BROWSER_FAVICON_FAVICON_UTIL_H_
+#define CHROME_BROWSER_FAVICON_FAVICON_UTIL_H_
+
+class GURL;
+
+namespace content {
+class RenderViewHost;
+}
+
+// Utility class for common favicon related code.
+class FaviconUtil {
+ public:
+  // Starts the download of the given favicon |url| from the given render view
+  // host. When the download is finished, an IconHostMsg_DidDownloadFavicon IPC
+  // message will be sent.
+  // Returns the unique id of the download request. The id will be sent in the
+  // IPC message.
+  static int DownloadFavicon(content::RenderViewHost* rvh,
+                             GURL url,
+                             int image_size);
+};
+
+#endif  // CHROME_BROWSER_FAVICON_FAVICON_UTIL_H_