Detach buffer in decodeAudioData

third_party/WebKit/Source/modules/webaudio/BaseAudioContext.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 266 matching lines @@
   DCHECK(isMainThread());
   DCHECK(audioData);
 
   ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
   ScriptPromise promise = resolver->promise();
 
   float rate = isContextClosed() ? closedContextSampleRate() : sampleRate();
 
   DCHECK_GT(rate, 0);
 
-  m_decodeAudioResolvers.insert(resolver);
-  m_audioDecoder.decodeAsync(audioData, rate, successCallback, errorCallback,
-                             resolver, this);
+  if (audioData->isNeutered()) {
+    // If audioData is detached (neutered) we need to reject the
+    // promise with an error.
+    DOMException* error = DOMException::create(
+        DataCloneError, "Cannot decode detached ArrayBuffer");
+    resolver->reject(error);
+    if (errorCallback) {
+      errorCallback->handleEvent(error);
+    }
+  } else {
+    // Detach the audio array buffer from the main thread and start
+    // async decoding of the data.
+    WTF::ArrayBufferContents bufferContents;
+    audioData->transfer(bufferContents);
+    DOMArrayBuffer* audio = DOMArrayBuffer::create(bufferContents);
+
+    m_decodeAudioResolvers.insert(resolver);
+    m_audioDecoder.decodeAsync(audio, rate, successCallback, errorCallback,
+                               resolver, this);
+  }
 
   return promise;
 }
 
 void BaseAudioContext::handleDecodeAudioData(
     AudioBuffer* audioBuffer,
     ScriptPromiseResolver* resolver,
     AudioBufferCallback* successCallback,
     AudioBufferCallback* errorCallback) {
   DCHECK(isMainThread());
@@ skipping 601 matching lines @@
 }
 
 SecurityOrigin* BaseAudioContext::getSecurityOrigin() const {
   if (getExecutionContext())
     return getExecutionContext()->getSecurityOrigin();
 
   return nullptr;
 }
 
 }  // namespace blink