2010-09-03 Chris Rogers <crogers@google.com>

      Reviewed by Kenneth Russell.

        Initial patch for audio engine: AudioBus and helper classes
        https://bugs.webkit.org/show_bug.cgi?id=34452

        No new tests since audio API is not yet implemented.

        * platform/audio/AudioBus.cpp: Added.
        (WebCore::AudioBus::AudioBus):
        (WebCore::AudioBus::setChannelMemory):
        (WebCore::AudioBus::zero):
        (WebCore::AudioBus::channelByType):
        (WebCore::AudioBus::topologyMatches):
        (WebCore::AudioBus::createBufferFromRange):
        (WebCore::AudioBus::maxAbsValue):
        (WebCore::AudioBus::normalize):
        (WebCore::AudioBus::scale):
        (WebCore::AudioBus::copyFrom):
        (WebCore::AudioBus::sumFrom):
        (WebCore::AudioBus::processWithGainFromMonoStereo):
        (WebCore::AudioBus::processWithGainFrom):
        (WebCore::AudioBus::copyWithGainFrom):
        (WebCore::AudioBus::sumWithGainFrom):
        * platform/audio/AudioBus.h: Added.
        (WebCore::AudioBus::numberOfChannels):
        (WebCore::AudioBus::channel):
        (WebCore::AudioBus::length):
        (WebCore::AudioBus::sampleRate):
        (WebCore::AudioBus::setSampleRate):
        (WebCore::AudioBus::setGain):
        (WebCore::AudioBus::gain):
        (WebCore::AudioBus::reset):
        (WebCore::AudioBus::AudioBus):
        * platform/audio/AudioSourceProvider.h: Added.
        (WebCore::AudioSourceProvider::~AudioSourceProvider):


git-svn-id: svn://svn.chromium.org/blink/trunk@66755 bbb929c8-8fbe-4397-9dbb-9b2b20218538