Define default values for options dictionaries for WebAudio

third_party/WebKit/Source/modules/webaudio/GainNode.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 151 matching lines @@
 GainNode* GainNode::Create(BaseAudioContext* context,
                            const GainOptions& options,
                            ExceptionState& exception_state) {
   GainNode* node = Create(*context, exception_state);
 
   if (!node)
     return nullptr;
 
   node->HandleChannelOptions(options, exception_state);
 
-  if (options.hasGain())
-    node->gain()->setValue(options.gain());
+  node->gain()->setValue(options.gain());
 
   return node;
 }
 
 AudioParam* GainNode::gain() const {
   return gain_;
 }
 
 DEFINE_TRACE(GainNode) {
   visitor->Trace(gain_);
   AudioNode::Trace(visitor);
 }
 
 }  // namespace blink