Support the copyFromChannel and copyToChannel methods on a WebAudio AudioBuffer
This is a required part of the WebAudio spec that Chrome currently does not support. These methods make reading and writing the contents of an AudioBuffer easier.
Firefox: Shipped
Internet Explorer: No public signals
Safari: No public signals
Web developers: No signals
These methods are new and upward compatible. This brings Chrome in line with the current WebAudio specification for AudioBuffers