Fix registerProtocolHandler implementation on Windows 8 and 10.

chrome/browser/shell_integration_win.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_SHELL_INTEGRATION_WIN_H_
 #define CHROME_BROWSER_SHELL_INTEGRATION_WIN_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
@@ skipping 16 matching lines @@
     const base::Closure& on_finished_callback);
 
 // Initiates an OS shell flow which (if followed by the user) should set
 // Chrome as the default handler for |protocol|. Returns false if the flow
 // cannot be initialized, if it is not supported (introduced for Windows 8)
 // or if the user cancels the operation. This is a blocking call and requires
 // a FILE thread. If Chrome is already default for |protocol|, no interactive
 // dialog will be shown and this method returns true.
 bool SetAsDefaultProtocolClientUsingIntentPicker(const std::string& protocol);
 
+// Initiates the interaction with the system settings for the default handler of
+// |protocol|. The function takes care of making sure |on_finished_callback|
+// will get called exactly once when the interaction is finished.
+void SetAsDefaultProtocolClientUsingSystemSettings(
+    const std::string& protocol,
+    const base::Closure& on_finished_callback);
+
 }  // namespace win
 }  // namespace shell_integration
 
 #endif  // CHROME_BROWSER_SHELL_INTEGRATION_WIN_H_