Refactor AccelerometerReader to provide an Observer

ash/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 
 gypi_values = exec_script("//build/gypi_to_gn.py",
                           [ rebase_path("ash.gyp") ],
                           "scope",
@@ skipping 261 matching lines @@
   ]
 
   if (!is_chromeos) {
     sources -= [
       # TODO(zork): fix this test to build on Windows. See: crosbug.com/26906
       "focus_cycler_unittest.cc",
 
       # All tests for multiple displays: not supported on Windows Ash.
       "wm/drag_window_resizer_unittest.cc",
 
+      # Accelerometer is only available on Chrome OS.
+      "wm/maximize_mode/maximize_mode_controller_unittest.cc",
+
       # Can't resize on Windows Ash. http://crbug.com/165962
       "magnifier/magnification_controller_unittest.cc",
       "wm/workspace/workspace_window_resizer_unittest.cc",
       "sticky_keys/sticky_keys_overlay_unittest.cc",
       "system/tray/media_security/multi_profile_media_tray_item_unittest.cc",
       "autoclick/autoclick_unittest.cc",
       "virtual_keyboard_controller_unittest.cc",
     ]
     sources += [
       #'<(SHARED_INTERMEDIATE_DIR)/ui/resources/ui_unscaled_resources.rc',  TODO(GYP)
@@ skipping 75 matching lines @@
     "//content/test:test_support",
     "//skia",
     "//testing/gtest",
     "//ui/accessibility",
   ]
 
   if (is_chromeos) {
     deps += [ "//ui/display" ]
   }
 }