Allow chrome to become the os default handler for arbitrary protocols on mac/win.

chrome/browser/platform_util.h

 // Copyright (c) 2011 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_PLATFORM_UTIL_H_
 #define CHROME_BROWSER_PLATFORM_UTIL_H_
 #pragma once
 
 #include <string>
 
@@ skipping 69 matching lines @@
 
 // Returns the channel for the installation. In branded builds, this will be
 // CHANNEL_STABLE, CHANNEL_BETA, CHANNEL_DEV, or CHANNEL_CANARY. In unbranded
 // builds, or in branded builds when the channel cannot be determined, this
 // will be CHANNEL_UNKNOWN.
 Channel GetChannel();
 
 // Returns true if the running browser can be set as the default browser.
 bool CanSetAsDefaultBrowser();
 
+// Returns true if the running browser can be set as the default client
+// application for the given protocol.
+bool CanSetAsDefaultProtocolClient(const std::string& protocol);
+
 }
 
 #endif  // CHROME_BROWSER_PLATFORM_UTIL_H_