Hook up the FocusController behind a flag.

ash/shell.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.
 
 #ifndef ASH_SHELL_H_
 #define ASH_SHELL_H_
 
 #include <utility>
 #include <vector>
 
@@ skipping 12 matching lines @@
 #include "ui/gfx/screen.h"
 #include "ui/gfx/size.h"
 
 class CommandLine;
 
 namespace aura {
 class EventFilter;
 class RootWindow;
 class Window;
 namespace client {
+class ActivationClient;
 class FocusClient;
 class StackingClient;
 class UserActionClient;
 }
 }
 namespace chromeos {
 class OutputConfigurator;
 }
 namespace content {
 class BrowserContext;
@@ skipping 458 matching lines @@
   scoped_ptr<UserActivityDetector> user_activity_detector_;
   scoped_ptr<VideoDetector> video_detector_;
   scoped_ptr<WindowCycleController> window_cycle_controller_;
   scoped_ptr<internal::FocusCycler> focus_cycler_;
   scoped_ptr<DisplayController> display_controller_;
   scoped_ptr<HighContrastController> high_contrast_controller_;
   scoped_ptr<MagnificationController> magnification_controller_;
   scoped_ptr<PartialMagnificationController> partial_magnification_controller_;
   scoped_ptr<aura::client::FocusClient> focus_client_;
   scoped_ptr<aura::client::UserActionClient> user_action_client_;
+  aura::client::ActivationClient* activation_client_;
   scoped_ptr<internal::MouseCursorEventFilter> mouse_cursor_filter_;
   scoped_ptr<internal::ScreenPositionController> screen_position_controller_;
   scoped_ptr<internal::SystemModalContainerEventFilter> modality_filter_;
   scoped_ptr<internal::EventClientImpl> event_client_;
 
   // An event filter that rewrites or drops an event.
   scoped_ptr<internal::EventRewriterEventFilter> event_rewriter_filter_;
 
   // An event filter that pre-handles key events while the partial
   // screenshot UI or the keyboard overlay is active.
@@ skipping 35 matching lines @@
 
   // For testing only: simulate that a modal window is open
   bool simulate_modal_window_open_for_testing_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_