[MediaRouter]Wires up issue manager in MediaRouterMojoImpl.

chrome/browser/media/router/test_helper.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/router/test_helper.h"
 
 namespace media_router {
 
+MockIssuesObserver::MockIssuesObserver(MediaRouter* router)
+    : IssuesObserver(router) {}
+MockIssuesObserver::~MockIssuesObserver() {}
+
 MockMediaSinksObserver::MockMediaSinksObserver(MediaRouter* router,
                                                const MediaSource& source)
     : MediaSinksObserver(router, source) {
 }
 MockMediaSinksObserver::~MockMediaSinksObserver() {
 }
 
 MockMediaRoutesObserver::MockMediaRoutesObserver(MediaRouter* router)
     : MediaRoutesObserver(router) {
 }
 MockMediaRoutesObserver::~MockMediaRoutesObserver() {
 }
 
 MockEventPageTracker::MockEventPageTracker() {
 }
 MockEventPageTracker::~MockEventPageTracker() {
 }
 
 }  // namespace media_router