AudioParam must support k-rate processing with audio-rate connections

AudioParam must support k-rate processing with audio-rate connections
https://bugs.webkit.org/show_bug.cgi?id=94385

Reviewed by Kenneth Russell.

Fully implement AudioParam *final* value calculation according to spec:
https://dvcs.w3.org/hg/audio/raw-file/tip/webaudio/specification.html#AudioParam

In particular, this covers the case where the parameter is k-rate, and we also
have audio-rate connections to the AudioParam.

* Modules/webaudio/AudioParam.cpp:
(WebCore::AudioParam::finalValue):
(WebCore):
(WebCore::AudioParam::calculateSampleAccurateValues):
(WebCore::AudioParam::calculateFinalValues):
* Modules/webaudio/AudioParam.h:
(AudioParam):
* Modules/webaudio/DelayDSPKernel.cpp:
(WebCore::DelayDSPKernel::process):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@125957 268f45cc-cd09-0410-ab3c-d52691b4dbfc