Use nullptr instead of 0 in WebAudio

Source/modules/webaudio/OfflineAudioContext.cpp

 /*
  * Copyright (C) 2012, 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 26 matching lines @@
 
 namespace blink {
 
 OfflineAudioContext* OfflineAudioContext::create(ExecutionContext* context, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate, ExceptionState& exceptionState)
 {
     // FIXME: add support for workers.
     if (!context || !context->isDocument()) {
         exceptionState.throwDOMException(
             NotSupportedError,
             "Workers are not supported.");
-        return 0;
+        return nullptr;
     }
 
     Document* document = toDocument(context);
 
     if (!numberOfFrames) {
         exceptionState.throwDOMException(SyntaxError, "number of frames cannot be zero.");
-        return 0;
+        return nullptr;
     }
 
     if (numberOfChannels > AudioContext::maxNumberOfChannels()) {
         exceptionState.throwDOMException(
             IndexSizeError,
             ExceptionMessages::indexOutsideRange<unsigned>(
                 "number of channels",
                 numberOfChannels,
                 0,
                 ExceptionMessages::InclusiveBound,
                 AudioContext::maxNumberOfChannels(),
                 ExceptionMessages::InclusiveBound));
-        return 0;
+        return nullptr;
     }
 
     if (!AudioUtilities::isValidAudioBufferSampleRate(sampleRate)) {
         exceptionState.throwDOMException(
             IndexSizeError,
             ExceptionMessages::indexOutsideRange(
                 "sampleRate", sampleRate,
                 AudioUtilities::minAudioBufferSampleRate(), ExceptionMessages::InclusiveBound,
                 AudioUtilities::maxAudioBufferSampleRate(), ExceptionMessages::InclusiveBound));
         return nullptr;
@@ skipping 35 matching lines @@
     }
 
     m_offlineResolver = ScriptPromiseResolver::create(scriptState);
     startRendering();
     return m_offlineResolver->promise();
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)