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

ash/ash.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
   },
   'includes': [
@@ skipping 46 matching lines @@
         'accelerators/accelerator_dispatcher.cc',
         'accelerators/accelerator_dispatcher.h',
         'accelerators/accelerator_filter.cc',
         'accelerators/accelerator_filter.h',
         'accelerators/accelerator_table.cc',
         'accelerators/accelerator_table.h',
         'accelerators/debug_commands.cc',
         'accelerators/debug_commands.h',
         'accelerators/exit_warning_handler.cc',
         'accelerators/exit_warning_handler.h',
+        'accelerators/key_hold_detector.cc',
+        'accelerators/key_hold_detector.h',
         'accelerators/focus_manager_factory.cc',
         'accelerators/focus_manager_factory.h',
+        'accelerators/magnifier_key_scroller.cc',
+        'accelerators/magnifier_key_scroller.h',
         'accelerators/nested_dispatcher_controller.cc',
         'accelerators/nested_dispatcher_controller.h',
+        'accelerators/spoken_feedback_toggler.cc',
+        'accelerators/spoken_feedback_toggler.h',
         'accessibility_delegate.h',
         'audio/sounds.cc',
         'audio/sounds.h',
         'autoclick/autoclick_controller.cc',
         'autoclick/autoclick_controller.h',
         'ash_constants.cc',
         'ash_constants.h',
         'ash_switches.cc',
         'ash_switches.h',
         'cancel_mode.cc',
@@ skipping 89 matching lines @@
         'ime/input_method_menu_item.h',
         'ime/input_method_menu_manager.cc',
         'ime/input_method_menu_manager.h',
         'ime/mode_indicator_view.cc',
         'ime/mode_indicator_view.h',
         'keyboard_uma_event_filter.cc',
         'keyboard_uma_event_filter.h',
         'magnifier/magnification_controller.cc',
         'magnifier/magnification_controller.h',
         'magnifier/magnifier_constants.h',
-        'magnifier/magnifier_key_scroller.cc',
-        'magnifier/magnifier_key_scroller.h',
         'magnifier/partial_magnification_controller.cc',
         'magnifier/partial_magnification_controller.h',
         'metrics/user_metrics_recorder.cc',
         'metrics/user_metrics_recorder.h',
         'multi_profile_uma.cc',
         'multi_profile_uma.h',
         'popup_message.cc',
         'popup_message.h',
         'root_window_controller.cc',
         'root_window_controller.h',
@@ skipping 442 matching lines @@
           'msvs_disabled_warnings': [ 4267, ],
         }],
         ['OS!="linux"', {
           'sources/': [
             ['exclude', 'system/monitor/tray_monitor.cc'],
             ['exclude', 'system/monitor/tray_monitor.h'],
           ],
         }],
         ['use_x11!=1', {
           'sources/': [
+            ['exclude', 'accelerators/key_hold_detector.cc'],
+            ['exclude', 'accelerators/key_hold_detector.h'],
+            ['exclude', 'accelerators/magnifier_key_scroller.cc'],
+            ['exclude', 'accelerators/magnifier_key_scroller.h'],
+            ['exclude', 'accelerators/spoken_feedback_toggler.cc'],
+            ['exclude', 'accelerators/spoken_feedback_toggler.h'],
             ['exclude', 'display/display_change_observer_chromeos.cc'],
             ['exclude', 'display/display_change_observer_chromeos.h'],
             ['exclude', 'display/display_error_observer_chromeos.cc'],
             ['exclude', 'display/display_error_observer_chromeos.h'],
-            ['exclude', 'magnifier/magnifier_key_scroller.cc'],
-            ['exclude', 'magnifier/magnifier_key_scroller.h'],
           ],
         }],
         ['chromeos==1', {
           'dependencies': [
             '../chromeos/chromeos.gyp:chromeos',
             # Ash #includes power_supply_properties.pb.h directly.
             '../chromeos/chromeos.gyp:power_manager_proto',
           ],
         }, { # else: chromeos!=1
           'sources/': [
@@ skipping 161 matching lines @@
         'ash',
         'ash_resources',
         'ash_test_support',
         'ash_with_content',
       ],
       'sources': [
         'accelerators/accelerator_commands_unittest.cc',
         'accelerators/accelerator_controller_unittest.cc',
         'accelerators/accelerator_filter_unittest.cc',
         'accelerators/accelerator_table_unittest.cc',
+        'accelerators/magnifier_key_scroller_unittest.cc',
         'accelerators/nested_dispatcher_controller_unittest.cc',
+        'accelerators/spoken_feedback_toggler_unittest.cc',
         'autoclick/autoclick_unittest.cc',
         'desktop_background/desktop_background_controller_unittest.cc',
         'desktop_background/wallpaper_resizer_unittest.cc',
         'dip_unittest.cc',
         'display/display_change_observer_chromeos_unittest.cc',
         'display/display_controller_unittest.cc',
         'display/display_error_observer_chromeos_unittest.cc',
         'display/display_info_unittest.cc',
         'display/display_manager_unittest.cc',
         'display/mirror_window_controller_unittest.cc',
         'display/virtual_keyboard_window_controller_unittest.cc',
         'display/mouse_cursor_event_filter_unittest.cc',
         'display/projecting_observer_chromeos_unittest.cc',
         'display/resolution_notification_controller_unittest.cc',
         'display/root_window_transformers_unittest.cc',
         'display/screen_position_controller_unittest.cc',
         'drag_drop/drag_drop_controller_unittest.cc',
         'drag_drop/drag_drop_tracker_unittest.cc',
         'extended_desktop_unittest.cc',
         'focus_cycler_unittest.cc',
         'ime/candidate_window_view_unittest.cc',
         'ime/input_method_menu_item_unittest.cc',
         'ime/input_method_menu_manager_unittest.cc',
         'keyboard_overlay/keyboard_overlay_delegate_unittest.cc',
         'keyboard_overlay/keyboard_overlay_view_unittest.cc',
         'magnifier/magnification_controller_unittest.cc',
-        'magnifier/magnifier_key_scroller_unittest.cc',
         'root_window_controller_unittest.cc',
         'screen_util_unittest.cc',
         'screensaver/screensaver_view_unittest.cc',
         'session_state_delegate_stub.cc',
         'session_state_delegate_stub.h',
         'shelf/scoped_observer_with_duplicated_sources_unittest.cc',
         'shelf/shelf_layout_manager_unittest.cc',
         'shelf/shelf_model_unittest.cc',
         'shelf/shelf_navigator_unittest.cc',
         'shelf/shelf_tooltip_manager_unittest.cc',
@@ skipping 108 matching lines @@
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         }],
         ['OS=="win" and win_use_allocator_shim==1', {
           'dependencies': [
             '../base/allocator/allocator.gyp:allocator',
           ],
         }],
         ['use_x11!=1', {
           'sources/': [
+            ['exclude', 'accelerators/magnifier_key_scroller_unittest.cc'],
+            ['exclude', 'accelerators/spoken_feedback_toggler_unittest.cc'],
             ['exclude', 'display/display_change_observer_chromeos_unittest.cc'],
             ['exclude', 'display/display_error_observer_chromeos_unittest.cc'],
-            ['exclude', 'magnifier/magnifier_key_scroller_unittest.cc'],
           ],
         }],
         ['chromeos==1', {
           'dependencies': [
             '../chromeos/chromeos.gyp:power_manager_proto',
           ],
           'sources': [
             'first_run/first_run_helper_unittest.cc',
           ],
         }, { # else: chromeos!=1
@@ skipping 88 matching lines @@
             },
           },
           'dependencies': [
             '../sandbox/sandbox.gyp:sandbox',
           ],
         }],
       ],
     },
   ],
 }