[Web Audio] createScriptProcessor throws IndexSizeError for valid arguments

[Web Audio] createScriptProcessor throws IndexSizeError for valid arguments
https://bugs.webkit.org/show_bug.cgi?id=173022

Reviewed by Sam Weinig.

Source/WebCore:

Updated test: webaudio/javascriptaudionode.html

The Web Audio spec (<https://webaudio.github.io/web-audio-api/>, 06 June 2017) defines a default behavior when
clients pass in a value of 0 for bufferSize to the createScriptProcessor() method.

* Modules/webaudio/AudioContext.cpp:
(WebCore::AudioContext::createScriptProcessor):
* Modules/webaudio/AudioContext.idl:
* Modules/webaudio/ScriptProcessorNode.cpp:
(WebCore::ScriptProcessorNode::create):
* Modules/webaudio/ScriptProcessorNode.h:

LayoutTests:

* webaudio/javascriptaudionode-expected.txt:
* webaudio/javascriptaudionode.html:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@217919 268f45cc-cd09-0410-ab3c-d52691b4dbfc