Enabling TabManager on testing browser process

chrome/test/base/testing_browser_process.h

 // Copyright (c) 2012 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.
 
 // An implementation of BrowserProcess for unit tests that fails for most
 // services. By preventing creation of services, we reduce dependencies and
 // keep the profile clean. Clients of this class must handle the NULL return
 // value, however.
 
 #ifndef CHROME_TEST_BASE_TESTING_BROWSER_PROCESS_H_
@@ skipping 161 matching lines @@
   scoped_refptr<printing::PrintPreviewDialogController>
       print_preview_dialog_controller_;
 #endif
 
   scoped_refptr<safe_browsing::SafeBrowsingService> sb_service_;
   std::unique_ptr<subresource_filter::RulesetService>
       subresource_filter_ruleset_service_;
 
   std::unique_ptr<network_time::NetworkTimeTracker> network_time_tracker_;
 
+  // |tab_manager_| is null by default and will be created when
+  // GetTabManager() is invoked on supported platforms.
+#if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
+  std::unique_ptr<memory::TabManager> tab_manager_;
+#endif
+
   // The following objects are not owned by TestingBrowserProcess:
   PrefService* local_state_;
   IOThread* io_thread_;
   net::URLRequestContextGetter* system_request_context_;
   rappor::RapporService* rappor_service_;
 
   std::unique_ptr<BrowserProcessPlatformPart> platform_part_;
 
 #if defined(ENABLE_EXTENSIONS)
   std::unique_ptr<MediaFileSystemRegistry> media_file_system_registry_;
@@ skipping 22 matching lines @@
 class TestingBrowserProcessInitializer {
  public:
   TestingBrowserProcessInitializer();
   ~TestingBrowserProcessInitializer();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestingBrowserProcessInitializer);
 };
 
 #endif  // CHROME_TEST_BASE_TESTING_BROWSER_PROCESS_H_