testing window['Audio'] is not sufficient

See also Issue 34 (Jun 2012).

I've tried running blockly on a Windows Server 2012 R2 computer in Internet 
Explorer 11 (11.0.9600.17031), but it didn't work.

Debugging showed that the

    var audioTest = new window['Audio']();

line in core/workspace_svg.js (in Blockly.WorkspaceSvg.prototype.loadAudio_) 
raised a short "Not implemented" exception.

The answer in 
http://stackoverflow.com/questions/20061959/js-audio-method-not-implemented-in-i
e-10-of-server-2008-r2 says: "sound support has been disabled (the default in 
windows server)" and apparently the

    if (!window['Audio']...

test is not enough in this case: window['Audio'] is a function, but 
window['Audio']() raises exception.

Unfortunately this exception aborts proper initialization of blockly.

Please try-catch the body of Blockly.WorkspaceSvg.prototype.loadAudio_ or 
something inside.

Original issue reported on code.google.com by kb.f12...@gmail.com on 12 Aug 2015 at 5:30

alexliuxiaoting / blockly

testing window['Audio'] is not sufficient #272