Enable WebAudio support on Android/x86.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index c984a481214fe98edf109c69585fa9462248c517..eaa14e33bd7da0baa0db0c0f26df5b9ce9c90e09 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -767,10 +767,10 @@
           'test_isolation_mode%': 'noop',
         }],
         # Whether Android ARM build uses OpenMAX DL FFT.
-        ['OS=="android" and target_arch=="arm" and android_webview_build==0', {
-          # Currently only supported on Android ARM, without webview.
-          # When enabled, this will also enable WebAudio on Android
-          # ARM.  Default is enabled.
+        ['OS=="android" and (target_arch=="arm" or target_arch=="ia32") and android_webview_build==0', {
+          # When set to 1, use_openmax_dl_fft will also make WebAudio
+          # available on Android. However, chrome://flags controls whether
+          # WebAudio is actually enabled.
           'use_openmax_dl_fft%': 1,
         }, {
           'use_openmax_dl_fft%': 0,
@@ -1653,6 +1653,11 @@
       ['use_titlecase_in_grd_files==1', {
         'grit_defines': ['-D', 'use_titlecase'],
       }],
+      ['OS=="android" and target_arch=="ia32"', {
+        # WebAudio on Android/x86 is disabled by default, unlike
+        # everywhere else, so use appropriate message.
+        'grit_defines': ['-D', 'use_webaudio_enable_message'],
+      }],
       ['use_third_party_translations==1', {
         'grit_defines': ['-D', 'use_third_party_translations'],
         'locales': [