[Media Router] Conditionally enable mDNS on Windows.

chrome/browser/media/router/test_helper.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_TEST_HELPER_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_TEST_HELPER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 127 matching lines @@
                     const SendRouteMessageCallback& callback));
   MOCK_METHOD2(ListenForRouteMessages,
                void(const mojo::String& route_id,
                     const ListenForRouteMessagesCallback& callback));
   MOCK_METHOD1(StopListeningForRouteMessages,
                void(const mojo::String& route_id));
   MOCK_METHOD1(OnPresentationSessionDetached,
                void(const mojo::String& route_id));
   MOCK_METHOD1(StartObservingMediaRoutes, void(const mojo::String& source));
   MOCK_METHOD1(StopObservingMediaRoutes, void(const mojo::String& source));
+  MOCK_METHOD0(EnableMdnsDiscovery, void());
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockMediaRouteProvider);
 };
 
 class MockMediaSinksObserver : public MediaSinksObserver {
  public:
   MockMediaSinksObserver(MediaRouter* router,
                          const MediaSource& source,
                          const GURL& origin);
@@ skipping 27 matching lines @@
  public:
   MockPresentationConnectionStateChangedCallback();
   ~MockPresentationConnectionStateChangedCallback();
   MOCK_METHOD1(Run,
                void(const content::PresentationConnectionStateChangeInfo&));
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_TEST_HELPER_H_