[web-audio-api] Clarify the exception codes thrown by AudioParam.exponentialRampToValueAtTime (#22)

> Originally reported on W3C Bugzilla [ISSUE-20822](https://www.w3.org/Bugs/Public/show_bug.cgi?id=20822) Tue, 29 Jan 2013 22:46:33 GMT
> Reported by Ehsan Akhgari [:ehsan]
> Assigned to 

The spec currently says:

"The value parameter is the value the parameter will exponentially ramp to at the given time. An exception will be thrown if this value is less than or equal to 0, or if the value at the time of the previous event is less than or equal to 0."

We need to clarify what exception gets raised in these cases.

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Reply to this email directly or view it on GitHub:
https://github.com/WebAudio/web-audio-api/issues/22