Support multiple HRTFDatabases for different sample-rates
https://bugs.webkit.org/show_bug.cgi?id=116183

Reviewed by Kenneth Russell.

Adapted from Blink:
https://codereview.chromium.org/14636011/

This removes the limitation which required OfflineAudioContexts to be created at native sample-rate

* Modules/webaudio/AudioContext.h:
(WebCore::AudioContext::hrtfDatabaseLoader):
(AudioContext):
* Modules/webaudio/OfflineAudioContext.cpp:
(WebCore::OfflineAudioContext::create):
* Modules/webaudio/OfflineAudioDestinationNode.cpp:
(WebCore::OfflineAudioDestinationNode::offlineRender):
* Modules/webaudio/PannerNode.cpp:
(WebCore::PannerNode::initialize):
(WebCore::PannerNode::setPanningModel):
* platform/audio/HRTFDatabaseLoader.cpp:
(WebCore):
(WebCore::HRTFDatabaseLoader::createAndLoadAsynchronouslyIfNecessary):
(WebCore::HRTFDatabaseLoader::~HRTFDatabaseLoader):
* platform/audio/HRTFDatabaseLoader.h:
(HRTFDatabaseLoader):
(WebCore::HRTFDatabaseLoader::loaderMap):
* platform/audio/HRTFPanner.cpp:
(WebCore::HRTFPanner::HRTFPanner):
(WebCore::HRTFPanner::calculateDesiredAzimuthIndexAndBlend):
(WebCore::HRTFPanner::pan):
* platform/audio/HRTFPanner.h:
(HRTFPanner):
* platform/audio/Panner.cpp:
(WebCore::Panner::create):
* platform/audio/Panner.h:
(WebCore):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150856 268f45cc-cd09-0410-ab3c-d52691b4dbfc
[Windows] Silence last crash to get bots green.

* platform/win/TestExpectations: 



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150857 268f45cc-cd09-0410-ab3c-d52691b4dbfc