How do I tell the Closure javascript compiler to not obfuscate the names of methods of webkitAudioContext?

Question

I use the webkitAudioContext constructor, which is native to webkit browsers, in my application written using Google Closure javascript.

After I compiled my javascript using Plovr in ADVANCED mode, I found that the decodeAudioData method of my webkitAudioContext object was renamed to the obfuscated term c. To be concete,

Before compilation:

var myAudioContext = new webkitAudioContext();
myAudioContext.decodeAudioData(fileData, myCallBackFunction);

After compilation:

(new webkitAudioContext).c(a,b);

How do I tell the Closure javascript compiler to not obfuscate the names of methods of webkitAudioContext? I have tried to call

goog.exportSymbol('webkitAudioContext.prototype.decodeAudioData', webkitAudioContext.prototype.decodeAudioData);

to no avail.

Answer 1

As Felix Kling mentioned in his comment, externs files are used to prevent renaming externally defined symbols. The Closure Compiler source code has externs files under the following directories:

trunk
 |-- externs
 |-- contrib
      |-- externs

The externs file contrib/externs/w3c_audio.js includes webkitAudioContext.

See the plovr externs config option.