Implement suspend() and resume() for OfflineAudioContext

Source/modules/webaudio/AudioDestinationNode.cpp

Index: Source/modules/webaudio/AudioDestinationNode.cpp
diff --git a/Source/modules/webaudio/AudioDestinationNode.cpp b/Source/modules/webaudio/AudioDestinationNode.cpp
index 920bb6cef15abd48fa14f9edccea93b494906984..93815449c25087664c262424f86bede8ddc73f70 100644
--- a/Source/modules/webaudio/AudioDestinationNode.cpp
+++ b/Source/modules/webaudio/AudioDestinationNode.cpp
@@ -95,6 +95,12 @@ void AudioDestinationHandler::render(AudioBus* sourceBus, AudioBus* destinationB
     releaseStore(&m_currentSampleFrame, newSampleFrame);
 }
 
+WebThread* AudioDestinationHandler::offlineRenderThread()
+{
+    ASSERT(context()->isOfflineContext());

[haraken, 2015/06/30 07:41:50]

ASSERT_NOT_REACHED() would be better.

[hongchan, 2015/06/30 18:52:10]

Done.

+    return nullptr;
+}
+
 // ----------------------------------------------------------------
 
 AudioDestinationNode::AudioDestinationNode(AudioContext& context)