Long press menu (shift+f6) to toggle spoken feedback.

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 69 matching lines @@
 class AshNativeCursorManager;
 class AutoclickController;
 class CapsLockDelegate;
 class DesktopBackgroundController;
 class DisplayController;
 class FirstRunHelper;
 class GPUSupport;
 class HighContrastController;
 class LockStateController;
 class MagnificationController;
-class MagnifierKeyScroller;
 class MediaDelegate;
 class MruWindowTracker;
 class NestedDispatcherController;
 class NewWindowDelegate;
 class PartialMagnificationController;
 class PowerButtonController;
 class WindowTreeHostFactory;
 class ScreenAsh;
 class SessionStateDelegate;
 class Shelf;
@@ skipping 598 matching lines @@
   // Controls video output device state.
   scoped_ptr<chromeos::OutputConfigurator> output_configurator_;
   scoped_ptr<internal::OutputConfiguratorAnimation>
       output_configurator_animation_;
   scoped_ptr<internal::DisplayErrorObserver> display_error_observer_;
   scoped_ptr<internal::ProjectingObserver> projecting_observer_;
 
   // Listens for output changes and updates the display manager.
   scoped_ptr<internal::DisplayChangeObserver> display_change_observer_;
 
-  scoped_ptr<MagnifierKeyScroller> magnifier_key_scroller_;
+  scoped_ptr<ui::EventHandler> magnifier_key_scroll_handler_;
+  scoped_ptr<ui::EventHandler> speech_feedback_handler_;
 #endif  // defined(USE_X11)
 #endif  // defined(OS_CHROMEOS)
 
   // |native_cursor_manager_| is owned by |cursor_manager_|, but we keep a
   // pointer to vend to test code.
   AshNativeCursorManager* native_cursor_manager_;
   views::corewm::CursorManager cursor_manager_;
 
   ObserverList<ShellObserver> observers_;
 
   // For testing only: simulate that a modal window is open
   bool simulate_modal_window_open_for_testing_;
 
   bool is_touch_hud_projection_enabled_;
 
   // Injected content::GPUDataManager support.
   scoped_ptr<GPUSupport> gpu_support_;
 
   DISALLOW_COPY_AND_ASSIGN(Shell);
 };
 
 }  // namespace ash
 
 #endif  // ASH_SHELL_H_