Use nullptr instead of 0 in WebAudio

Source/modules/webaudio/ScriptProcessorNode.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 55 matching lines @@
         break;
     case 256:
     case 512:
     case 1024:
     case 2048:
     case 4096:
     case 8192:
     case 16384:
         break;
     default:
-        return 0;
+        return nullptr;
     }
 
     if (!numberOfInputChannels && !numberOfOutputChannels)
-        return 0;
+        return nullptr;
 
     if (numberOfInputChannels > AudioContext::maxNumberOfChannels())
-        return 0;
+        return nullptr;
 
     if (numberOfOutputChannels > AudioContext::maxNumberOfChannels())
-        return 0;
+        return nullptr;
 
     return new ScriptProcessorNode(context, sampleRate, bufferSize, numberOfInputChannels, numberOfOutputChannels);
 }
 
 ScriptProcessorNode::ScriptProcessorNode(AudioContext* context, float sampleRate, size_t bufferSize, unsigned numberOfInputChannels, unsigned numberOfOutputChannels)
     : AudioNode(NodeTypeJavaScript, context, sampleRate)
     , m_doubleBufferIndex(0)
     , m_doubleBufferIndexForEvent(0)
     , m_bufferSize(bufferSize)
     , m_bufferReadWriteIndex(0)
@@ skipping 205 matching lines @@
 DEFINE_TRACE(ScriptProcessorNode)
 {
     visitor->trace(m_inputBuffers);
     visitor->trace(m_outputBuffers);
     AudioNode::trace(visitor);
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)