[Media Router] Conditionally enable mDNS on Windows.

chrome/browser/media/android/router/media_router_android.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 "chrome/browser/media/android/router/media_router_android.h"
 
 #include <string>
 #include <utility>
 #include <vector>
 
@@ skipping 219 matching lines @@
 }
 
 void MediaRouterAndroid::AddIssue(const Issue& issue) {
   NOTIMPLEMENTED();
 }
 
 void MediaRouterAndroid::ClearIssue(const Issue::Id& issue_id) {
   NOTIMPLEMENTED();
 }
 
+void MediaRouterAndroid::OnUserGesture() {
+}
+
 void MediaRouterAndroid::DetachRoute(const MediaRoute::Id& route_id) {
   JNIEnv* env = base::android::AttachCurrentThread();
   ScopedJavaLocalRef<jstring> jroute_id =
           base::android::ConvertUTF8ToJavaString(env, route_id);
   Java_ChromeMediaRouter_detachRoute(
       env, java_media_router_.obj(), jroute_id.obj());
 }
 
 bool MediaRouterAndroid::RegisterMediaSinksObserver(
     MediaSinksObserver* observer) {
@@ skipping 201 matching lines @@
   scoped_ptr<content::PresentationSessionMessage> message(
       new content::PresentationSessionMessage(content::TEXT));
   message->message = ConvertJavaStringToUTF8(env, jmessage);
   session_messages.push_back(std::move(message));
 
   FOR_EACH_OBSERVER(PresentationSessionMessagesObserver, *observer_list,
                     OnMessagesReceived(session_messages, true));
 }
 
 }  // namespace media_router