Merge 144417

Source/WebCore/Modules/webaudio/AudioNodeInput.cpp

Index: Source/WebCore/Modules/webaudio/AudioNodeInput.cpp
===================================================================
--- Source/WebCore/Modules/webaudio/AudioNodeInput.cpp	(revision 145455)
+++ Source/WebCore/Modules/webaudio/AudioNodeInput.cpp	(working copy)
@@ -154,7 +154,9 @@
 
     for (HashSet<AudioNodeOutput*>::iterator i = m_outputs.begin(); i != m_outputs.end(); ++i) {
         AudioNodeOutput* output = *i;
-        maxChannels = max(maxChannels, output->bus()->numberOfChannels());
+        // Use output()->numberOfChannels() instead of output->bus()->numberOfChannels(),
+        // because the calling of AudioNodeOutput::bus() is not safe here.
+        maxChannels = max(maxChannels, output->numberOfChannels());
     }
     
     return maxChannels;