Remove the WEB_AUDIO compile time flag

third_party/WebKit/Source/build/features.gypi

 #
 # Copyright (C) 2009 Google Inc. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 49 matching lines @@
         # Use concatenated HRTF impulse responses
         'feature_defines': ['WTF_USE_CONCATENATED_IMPULSE_RESPONSES=1'],
       }],
       ['OS=="android"', {
         'feature_defines': [
           'WTF_USE_LOW_QUALITY_IMAGE_INTERPOLATION=1'
         ],
       }, { # OS!=android
         'feature_defines': [
           'ENABLE_INPUT_MULTIPLE_FIELDS_UI=1',
-          'ENABLE_WEB_AUDIO=1',
           'WTF_USE_ICCJPEG=1',
           'WTF_USE_QCMSLIB=1'
         ],
       }],
       ['OS=="mac"', {
         'feature_defines': [
           'WTF_USE_NEW_THEME=1'
         ],
       }],
       # Mac OS X uses Accelerate.framework FFT by default instead of FFmpeg.
       ['OS!="mac" and OS!="android"', {
         'feature_defines': [
           'WTF_USE_WEBAUDIO_FFMPEG=1',
         ],
       }],
       ['OS=="android" and use_openmax_dl_fft!=0', {
         'feature_defines': [
           'WTF_USE_WEBAUDIO_OPENMAX_DL_FFT=1',
-          # Enabling the FFT is enough to enable WebAudio support to
-          # allow most WebAudio features to work on Android.
-          'ENABLE_WEB_AUDIO=1',
         ],
       }],
       ['use_default_render_theme==1', {
         'feature_defines': [
           'WTF_USE_DEFAULT_RENDER_THEME=1',
         ],
       }],
       ['enable_oilpan==1', {
         'feature_defines': [
           'ENABLE_OILPAN=1',
@@ skipping 13 matching lines @@
         'feature_defines': [
           'LINK_CORE_MODULES_SEPARATELY',
         ],
       }],
     ],
 
     # shared build only. If set to 1, link web, core and modules separately.
     'link_core_modules_separately%': '<(link_core_modules_separately)',
   },
 }