Add a new audio extension event OnLevelChanged.

extensions/extensions.gypi

Index: extensions/extensions.gypi
diff --git a/extensions/extensions.gypi b/extensions/extensions.gypi
index 03c3ae79e7b865e8fb396ea5c24b09afabb15d1d..e879a357b2af10babeaccc507b58cf15bfc6ce3a 100644
--- a/extensions/extensions.gypi
+++ b/extensions/extensions.gypi
@@ -792,18 +792,15 @@
       'browser/api/vpn_provider/vpn_service_factory.h',
     ],
     'extensions_browser_sources_nonchromeos': [
-      'browser/api/document_scan/document_scan_interface_nonchromeos.cc',
-    ],
-    'extensions_browser_sources_nonlinux': [
       'browser/api/audio/audio_service.cc',

[asargent_no_longer_on_chrome, 2015/03/17 16:21:17]

Just to make sure I'm understanding this change, are we doing it because the
only platform where this API works is ChromeOS? I.e. the audio_service_linux.cc
implementation code had no differences from the audio_service.cc file? (both are
empty stub implementations that don't actually do anything?)

[jennyz, 2015/03/17 18:17:28]

Yes.

+      'browser/api/document_scan/document_scan_interface_nonchromeos.cc',
     ],
     'extensions_browser_sources_win_or_mac': [
       'browser/api/networking_private/networking_private_event_router_nonchromeos.cc',
       'browser/api/networking_private/networking_private_service_client.cc',
       'browser/api/networking_private/networking_private_service_client.h',
     ],
-    'extensions_browser_sources_linux_nonchromeos': [
-      'browser/api/audio/audio_service_linux.cc',
+    'extensions_browser_sources_linux_nonchromeos': [      
       'browser/api/networking_private/network_config_dbus_constants_linux.cc',
       'browser/api/networking_private/network_config_dbus_constants_linux.h',
       'browser/api/networking_private/networking_private_event_router_nonchromeos.cc',