Add BackgroundModeOptimizer that can restart the browser

chrome/browser/background/background_mode_manager_unittest.cc

 // Copyright (c) 2011 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/background/background_mode_manager.h"
 
 #include <stddef.h>
 
 #include <memory>
 #include <string>
@@ skipping 243 matching lines @@
     // Deleting our testing profile may have the side-effect of disabling
     // background mode if it was enabled for that profile (explicitly note that
     // here to satisfy StrictMock requirements.
     EXPECT_CALL(*manager_, EnableLaunchOnStartup(false)).Times(AtMost(1));
     profile_manager_->DeleteAllTestingProfiles();
     Mock::VerifyAndClearExpectations(manager_.get());
 
     // We're getting ready to shutdown the message loop. Clear everything out!
     base::RunLoop().RunUntilIdle();
 
-    test_keep_alive_.reset();
-
     // TestBackgroundModeManager has dependencies on the infrastructure.
     // It should get cleared first.
     manager_.reset();
 
+    // Now that the background manager is destroyed, the test KeepAlive can be
+    // cleared without having |manager_| attempt to perform optimizations.
+    test_keep_alive_.reset();
+
     // The Profile Manager references the Browser Process.
     // The Browser Process references the Notification UI Manager.
     // The Notification UI Manager references the Message Center.
     // As a result, we have to clear the browser process state here
     // before tearing down the Message Center.
     profile_manager_.reset();
 
     // Message Center shutdown must occur after the KeepAlive is released
     // because clearing it will end up referencing the message center.
     message_center::MessageCenter::Shutdown();
@@ skipping 739 matching lines @@
   // When the background mode pref is enabled and there are pending triggers
   // they will be registered and the user will be notified.
   EXPECT_CALL(manager, EnableLaunchOnStartup(true));
   g_browser_process->local_state()->SetBoolean(prefs::kBackgroundModeEnabled,
                                                true);
   Mock::VerifyAndClearExpectations(&manager);
   ASSERT_EQ(1, manager.GetBackgroundClientCountForProfile(profile_));
   AssertBackgroundModeActive(manager);
   ASSERT_TRUE(manager.HasShownBalloon());
 }