I 'm not challenging the importance of enable webaudio, I'm saying find a right way to do. 

https://code.google.com/p/chromium/codesearch#search/&q=kEnableWebAudio&sq=package:chromium&type=cs shows me only 3 more files need to change.
* `src/content/child/runtime_features.cc`
* `src/content/browser/renderer_host/render_view_host_impl.cc`
* `src/content/browser/renderer_host/render_process_host_impl.cc`

Seems you do plan to enable it on upstream, so fix in right way first. Please keep in mind the crosswwalk contribute guidelines - try to upstream first.