Keep AudioSourceNode from premature GC with ScriptWrappable::hasPendingActivity()

third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.cpp

 /*
  * Copyright (C) 2010, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 772 matching lines @@
     ASSERT(isMainThread());
     AutoLocker locker(this);
 
     m_activeSourceNodes.append(node);
     node->handler().makeConnection();
 }
 
 void AbstractAudioContext::releaseActiveSourceNodes()
 {
     ASSERT(isMainThread());
-    for (auto& sourceNode : m_activeSourceNodes)
+    AutoLocker locker(this);
+
+    for (AudioNode* sourceNode : m_activeSourceNodes) {
+
+        // NOTE: this check makes the renderer crash.

[hongchan, 2016/02/19 00:46:47]

It is necessary to half the active source node. Otherwise the source node in the
'playing' or 'scheduled' state will leak. However, this check causes crashes in
several layout tests. Not sure why.

+        if (sourceNode->handler().nodeType() == AudioHandler::NodeTypeOscillator || AudioHandler::NodeTypeAudioBufferSource) {
+            AudioScheduledSourceNode* scheduledSourceNode = static_cast<AudioScheduledSourceNode*>(sourceNode);
+            scheduledSourceNode->releaseFromContext();
+        }
+
         sourceNode->handler().breakConnection();
+    }
 
     m_activeSourceNodes.clear();
 }
 
 void AbstractAudioContext::handleStoppableSourceNodes()
 {
     ASSERT(isGraphOwner());
 
     // Find AudioBufferSourceNodes to see if we can stop playing them.
     for (AudioNode* node : m_activeSourceNodes) {
@@ skipping 142 matching lines @@
 SecurityOrigin* AbstractAudioContext::securityOrigin() const
 {
     if (executionContext())
         return executionContext()->securityOrigin();
 
     return nullptr;
 }
 
 } // namespace blink