Repost offline rendering task if GC prevents.

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

 /*
  * Copyright (C) 2011, 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 164 matching lines @@
 
   unsigned number_of_channels;
   Vector<float*> destinations;
   {
     // Main thread GCs cannot happen while we're reading out channel
     // data. Detect that condition by trying to take the cross-thread
     // persistent lock which is held while a GC runs. If the lock is
     // already held, simply delay rendering until the next quantum.
     CrossThreadPersistentRegion::LockScope gc_lock(
         ProcessHeap::GetCrossThreadPersistentRegion(), true);
-    if (!gc_lock.HasLock())
+    if (!gc_lock.HasLock()) {
+      // To ensure that the rendering step eventually happens, repost.
+      render_thread_->GetWebTaskRunner()->PostTask(
+          BLINK_FROM_HERE,
+          Bind(&OfflineAudioDestinationHandler::DoOfflineRendering,
+               WrapPassRefPtr(this)));
       return;
+    }
 
     number_of_channels = render_target_->numberOfChannels();
     destinations.ReserveInitialCapacity(number_of_channels);
     for (unsigned i = 0; i < number_of_channels; ++i)
       destinations.push_back(render_target_->getChannelData(i).View()->Data());
   }
 
   // Reset the suspend flag.
   should_suspend_ = false;
 
@@ skipping 161 matching lines @@
   SetHandler(OfflineAudioDestinationHandler::Create(*this, render_target));
 }
 
 OfflineAudioDestinationNode* OfflineAudioDestinationNode::Create(
     BaseAudioContext* context,
     AudioBuffer* render_target) {
   return new OfflineAudioDestinationNode(*context, render_target);
 }
 
 }  // namespace blink