Add --enable-speech-input switch and set ENABLE_INPUT_SPEECH=1

build/features_override.gypi

 # Copyright (c) 2009 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.
 
 # This file is only included in full-chromium builds, and overrides the
 # feature_defines variable in third_party/WebKit/WebKit/chromium/features.gypi.
 {
   'variables': {
     # WARNING: This list of strings completely replaces the list in
     # features.gypi. Therefore, if an enable is listed in features.gypi
     # but not listed below, it will revert to its hardcoded webkit value.
     'feature_defines': [
       'ENABLE_3D_CANVAS=1',
       'ENABLE_BLOB_SLICE=1',
       'ENABLE_CHANNEL_MESSAGING=1',
       'ENABLE_DASHBOARD_SUPPORT=0',
       'ENABLE_DATABASE=1',
       'ENABLE_DATAGRID=0',
       'ENABLE_DEVICE_ORIENTATION=1',
       'ENABLE_DIRECTORY_UPLOAD=1',
       'ENABLE_DOM_STORAGE=1',
       'ENABLE_EVENTSOURCE=1',
       'ENABLE_FILE_READER=1',
       'ENABLE_FILTERS=1',
       'ENABLE_GEOLOCATION=1',
       'ENABLE_ICONDATABASE=0',
       'ENABLE_INDEXED_DATABASE=1',
+      'ENABLE_INPUT_SPEECH=1',
       'ENABLE_JAVASCRIPT_DEBUGGER=1',
       'ENABLE_JSC_MULTIPLE_THREADS=0',
       'ENABLE_METER_TAG=1',
       'ENABLE_NOTIFICATIONS=1',
       'ENABLE_OFFLINE_WEB_APPLICATIONS=1',
       'ENABLE_OPENTYPE_SANITIZER=1',
       'ENABLE_ORIENTATION_EVENTS=0',
       'ENABLE_PROGRESS_TAG=1',
       'ENABLE_RUBY=1',
       'ENABLE_SANDBOX=1',
@@ skipping 44 matching lines @@
     # require changes in gyp.
   },
 
 }
 
 # Local Variables:
 # tab-width:2
 # indent-tabs-mode:nil
 # End:
 # vim: set expandtab tabstop=2 shiftwidth=2: