Implement suspend() and resume() for OfflineAudioContext

third_party/WebKit/Source/modules/webaudio/DeferredTaskHandler.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 42 matching lines @@
         return true;
     }
     return m_contextGraphMutex.tryLock();
 }
 
 void DeferredTaskHandler::unlock()
 {
     m_contextGraphMutex.unlock();
 }
 
+void DeferredTaskHandler::offlineLock()
+{
+    // It is safe to lock the audio thread for offline rendering, but
+    // let us have RELEASE_ASSERT here to make sure to explicitly crash rather
+    // than accidentally blocking the audio thread.
+    RELEASE_ASSERT(isAudioThread());

[Raymond Toy, 2015/10/21 18:22:45]

Maybe use RELEASE_ASSERT_WITH_MESSAGE so a simple message is printed before we
crash.  Then we get some useful information even if the stacktrace is broken for
some reason.

[hongchan, 2015/10/22 18:23:48]

Done.

+
+    m_contextGraphMutex.lock();
+}
+
 #if ENABLE(ASSERT)
 bool DeferredTaskHandler::isGraphOwner()
 {
     return m_contextGraphMutex.locked();
 }
 #endif
 
 void DeferredTaskHandler::addDeferredBreakConnection(AudioHandler& node)
 {
     ASSERT(isAudioThread());
@@ skipping 188 matching lines @@
 {
     ASSERT(isMainThread());
     AutoLocker locker(*this);
     m_renderingOrphanHandlers.clear();
     m_deletableOrphanHandlers.clear();
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)