[Media Router] Add UMA metrics for media route controller creation

chrome/browser/media/router/mojo/media_router_mojo_metrics.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_MEDIA_ROUTER_MOJO_MEDIA_ROUTER_MOJO_METRICS_H_
 #define CHROME_BROWSER_MEDIA_ROUTER_MOJO_MEDIA_ROUTER_MOJO_METRICS_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/time/time.h"
 #include "chrome/common/media_router/route_request_result.h"
@@ skipping 86 matching lines @@
   // Records the outcome of a join route request to the Media Route Provider
   // Manager.
   static void RecordJoinRouteResultCode(
       RouteRequestResult::ResultCode result_code);
 
   // Records the outcome of a call to terminateRoute() on the Media Route
   // Provider Manager.
   static void RecordMediaRouteProviderTerminateRoute(
       RouteRequestResult::ResultCode result_code);
 
+  // Records whether the Media Route Provider succeeded or failed to create a
+  // controller for a media route.
+  static void RecordMediaRouteControllerCreationResult(bool success);
+
  private:
   FRIEND_TEST_ALL_PREFIXES(MediaRouterMojoMetricsTest,
                            TestGetMediaRouteProviderVersion);
 
   // Returns the version status of the Media Router component extension.
   static MediaRouteProviderVersion GetMediaRouteProviderVersion(
       const base::Version& extension_version,
       const base::Version& browser_version);
 };
 
 }  // namespace media_router
 
 #endif  // CHROME_BROWSER_MEDIA_ROUTER_MOJO_MEDIA_ROUTER_MOJO_METRICS_H_