Fix AudioNode.disconnect() to support selective disconnection.

Source/modules/webaudio/AudioNodeOutput.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 172 matching lines @@
 
 void AudioNodeOutput::disconnectAllInputs()
 {
     ASSERT(context()->isGraphOwner());
 
     // AudioNodeInput::disconnect() changes m_inputs by calling removeInput().
     while (!m_inputs.isEmpty())
         m_inputs.begin()->key->disconnect(*this);
 }
 
+void AudioNodeOutput::disconnectInput(AudioNodeInput& input)
+{
+    ASSERT(context()->isGraphOwner() && isConnectedWithInput(input));
+    input.disconnect(*this);
+}
+
+void AudioNodeOutput::disconnectAudioParam(AudioParam& param)
+{
+    ASSERT(context()->isGraphOwner() && isConnectedWithAudioParam(param));
+    param.disconnect(*this);
+}
+
 void AudioNodeOutput::addParam(AudioParam& param)
 {
     ASSERT(context()->isGraphOwner());
     m_params.add(&param);
 }
 
 void AudioNodeOutput::removeParam(AudioParam& param)
 {
     ASSERT(context()->isGraphOwner());
     m_params.remove(&param);
 }
 
 void AudioNodeOutput::disconnectAllParams()
 {
     ASSERT(context()->isGraphOwner());
 
     // AudioParam::disconnect() changes m_params by calling removeParam().
     while (!m_params.isEmpty())
         (*m_params.begin())->disconnect(*this);
 }
 
 void AudioNodeOutput::disconnectAll()
 {
     disconnectAllInputs();
     disconnectAllParams();
 }
 
+bool AudioNodeOutput::isConnectedWithInput(AudioNodeInput& input)

[Raymond Toy, 2015/02/11 21:31:18]

ConnectedWithInput or ConnectedToInput? I think the latter reads better.  Same
with AudioParam below.

[hongchan, 2015/02/12 18:38:01]

Done.

+{
+    ASSERT(context()->isGraphOwner());
+    return m_inputs.contains(&input);
+}
+
+bool AudioNodeOutput::isConnectedWithAudioParam(AudioParam& param)
+{
+    ASSERT(context()->isGraphOwner());
+    return m_params.contains(&param);
+}
+
 void AudioNodeOutput::disable()
 {
     ASSERT(context()->isGraphOwner());
 
     if (m_isEnabled) {
         m_isEnabled = false;
         for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i)
             i->key->disable(*this);
     }
 }
 
 void AudioNodeOutput::enable()
 {
     ASSERT(context()->isGraphOwner());
 
     if (!m_isEnabled) {
         m_isEnabled = true;
         for (InputsIterator i = m_inputs.begin(); i != m_inputs.end(); ++i)
             i->key->enable(*this);
     }
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)