[Media Router] Convert to use typemaps for media_router.mojom.

chrome/browser/media/router/media_source.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 CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SOURCE_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SOURCE_H_
 
 #include <stddef.h>
 
 #include <ostream>
@@ skipping 28 matching lines @@
   // Used for logging.
   std::string ToString() const;
 
   // Hash operator for hash containers.
   struct Hash {
     size_t operator()(const MediaSource& source) const {
       return base::Hash(source.id());
     }
   };
 
+  // Used by Mojo.

[mark a. foltz, 2017/02/07 20:02:48]

Please declare with other ctors.

[imcheng, 2017/02/07 20:36:18]

Done.

+  MediaSource();
+
  private:
   MediaSource::Id id_;
   GURL url_;
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MEDIA_SOURCE_H_