Refactor AccelerometerReader to provide an Observer

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',
     # These files lists are shared with the GN build.
     'ash_sources': [
@@ skipping 12 matching lines @@
       '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/spoken_feedback_toggler.cc',
       'accelerators/spoken_feedback_toggler.h',
-      'accelerometer/accelerometer_controller.cc',
-      'accelerometer/accelerometer_controller.h',
-      'accelerometer/accelerometer_observer.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_export.h',
       'ash_switches.cc',
       'ash_switches.h',
@@ skipping 1253 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'ash_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }