Implement WebMediaPlayerClientImpl::audioSourceProvider() and interface into chromium

      https://bugs.webkit.org/show_bug.cgi?id=66441

Reviewed by Darin Fisher.

* public/WebAudioSourceProvider.h: Added.
(WebKit::WebAudioSourceProvider::~WebAudioSourceProvider):
* public/WebMediaPlayer.h:
(WebKit::WebMediaPlayer::audioSourceProvider):
* src/WebMediaPlayerClientImpl.cpp:
(WebKit::WebMediaPlayerClientImpl::audioSourceProvider):
(WebKit::WebMediaPlayerClientImpl::AudioSourceProviderImpl::provideInput):
* src/WebMediaPlayerClientImpl.h:
(WebKit::WebMediaPlayerClientImpl::AudioSourceProviderImpl::AudioSourceProviderImpl):
(WebKit::WebMediaPlayerClientImpl::AudioSourceProviderImpl::~AudioSourceProviderImpl):
(WebKit::WebMediaPlayerClientImpl::AudioSourceProviderImpl::initialize):


git-svn-id: svn://svn.chromium.org/blink/trunk@93367 bbb929c8-8fbe-4397-9dbb-9b2b20218538