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

chrome/browser/media/router/media_sink.cc

 // 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.
 
 #include "base/i18n/string_compare.h"
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/browser/media/router/media_sink.h"
 #include "third_party/icu/source/i18n/unicode/coll.h"
 
 namespace media_router {
 
 MediaSink::MediaSink(const MediaSink::Id& sink_id,
                      const std::string& name,
                      const MediaSink::IconType icon_type)
     : sink_id_(sink_id), name_(name), icon_type_(icon_type) {}
 
 MediaSink::MediaSink(const MediaSink& other) = default;
 
+MediaSink::MediaSink() {}
+
 MediaSink::~MediaSink() {
 }
 
 bool MediaSink::Equals(const MediaSink& other) const {
   return sink_id_ == other.sink_id_;
 }
 
 bool MediaSink::CompareUsingCollator(const MediaSink& other,
                                      const icu::Collator* collator) const {
   if (icon_type_ != other.icon_type_)
@@ skipping 11 matching lines @@
     // available.
     int val = name_.compare(other.name_);
     if (val)
       return val < 0;
   }
 
   return sink_id_ < other.sink_id_;
 }
 
 }  // namespace media_router