[sync] WebContentsObserver based sessions notifications

components/sync_sessions/fake_sync_sessions_client.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 COMPONENTS_SYNC_SESSIONS_FAKE_SYNC_SESSIONS_CLIENT_H_
 #define COMPONENTS_SYNC_SESSIONS_FAKE_SYNC_SESSIONS_CLIENT_H_
 
 #include <memory>
 
 #include "base/macros.h"
 #include "components/sync_sessions/sync_sessions_client.h"
 
 namespace sync_sessions {
 
 // Fake implementation of a SyncSessionsClient for testing.
 class FakeSyncSessionsClient : public SyncSessionsClient {
  public:
   FakeSyncSessionsClient();
   ~FakeSyncSessionsClient() override;
 
   // SyncSessionsClient:
   bookmarks::BookmarkModel* GetBookmarkModel() override;
   favicon::FaviconService* GetFaviconService() override;
   history::HistoryService* GetHistoryService() override;
   bool ShouldSyncURL(const GURL& url) const override;
   SyncedWindowDelegatesGetter* GetSyncedWindowDelegatesGetter() override;
-  std::unique_ptr<LocalSessionEventRouter> GetLocalSessionEventRouter()
-      override;
+  LocalSessionEventRouter* GetLocalSessionEventRouter() override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FakeSyncSessionsClient);
 };
 
 }  // namespace sync_sessions
 
 #endif  // COMPONENTS_SYNC_SESSIONS_FAKE_SYNC_SESSIONS_CLIENT_H_