Refactor the TrayAudio code so that it can be used by other platforms.

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 245 matching lines @@
         'shell.cc',
         'shell.h',
         'shell_delegate.h',
         'shell_factory.h',
         'shell_window_ids.h',
         'sticky_keys/sticky_keys_state.h',
         'sticky_keys/sticky_keys_controller.cc',
         'sticky_keys/sticky_keys_controller.h',
         'sticky_keys/sticky_keys_overlay.cc',
         'sticky_keys/sticky_keys_overlay.h',
+        'system/audio/audio_observer.h',
+        'system/audio/tray_audio.cc',
+        'system/audio/tray_audio.h',
+        'system/audio/tray_audio_delegate.h',
+        'system/audio/volume_view.cc',
+        'system/audio/volume_view.h',
         'system/bluetooth/bluetooth_observer.h',
         'system/bluetooth/tray_bluetooth.cc',
         'system/bluetooth/tray_bluetooth.h',
         'system/brightness_control_delegate.h',
-        'system/chromeos/audio/tray_audio.cc',
-        'system/chromeos/audio/tray_audio.h',
+        'system/chromeos/audio/audio_detailed_view.cc',
+        'system/chromeos/audio/audio_detailed_view.h',
+        'system/chromeos/audio/tray_audio_chromeos.cc',
+        'system/chromeos/audio/tray_audio_chromeos.h',
+        'system/chromeos/audio/tray_audio_delegate_chromeos.cc',
+        'system/chromeos/audio/tray_audio_delegate_chromeos.h',
         'system/chromeos/enterprise/enterprise_domain_observer.h',
         'system/chromeos/brightness/brightness_controller_chromeos.cc',
         'system/chromeos/brightness/brightness_controller_chromeos.h',
         'system/chromeos/brightness/tray_brightness.cc',
         'system/chromeos/brightness/tray_brightness.h',
         'system/chromeos/enterprise/tray_enterprise.h',
         'system/chromeos/enterprise/tray_enterprise.cc',
         'system/chromeos/keyboard_brightness_controller.cc',
         'system/chromeos/keyboard_brightness_controller.h',
         'system/chromeos/label_tray_view.h',
@@ skipping 803 matching lines @@
             },
           },
           'dependencies': [
             '../sandbox/sandbox.gyp:sandbox',
           ],
         }],
       ],
     },
   ],
 }