Deactivated the intelligibility enhancement functionality by default

webrtc/media/media.gyp

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 {
   'includes': [ '../build/common.gypi', ],
@@ skipping 107 matching lines @@
         ['build_usrsctp==1', {
           'include_dirs': [
             # TODO(jiayl): move this into the direct_dependent_settings of
             # usrsctp.gyp.
             '<(DEPTH)/third_party/usrsctp/usrsctplib',
           ],
           'dependencies': [
             '<(DEPTH)/third_party/usrsctp/usrsctp.gyp:usrsctplib',
           ],
         }],
+        ['enable_intelligibility_enhancer==1', {
+          'defines': ['WEBRTC_INTELLIGIBILITY_ENHANCER=1',],
+        }, {
+          'defines': ['WEBRTC_INTELLIGIBILITY_ENHANCER=0',],
+        }],
         ['build_with_chromium==1', {
           'dependencies': [
             '<(webrtc_root)/modules/modules.gyp:video_capture',
           ],
         }, {
           'defines': [
             'HAVE_WEBRTC_VIDEO',
             'HAVE_WEBRTC_VOICE',
           ],
           'direct_dependent_settings': {
@@ skipping 224 matching lines @@
               'sources': [
                 'rtc_media_unittests.isolate',
               ],
             },
           ],
         }],
       ],  # conditions
     }],  # include_tests==1
   ],  # conditions
 }