Make reduction value of dynamics compressor zero when no sources are connected

Source/modules/webaudio/AudioNode.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 71 matching lines @@
 void AudioNode::initialize()
 {
     m_isInitialized = true;
 }
 
 void AudioNode::uninitialize()
 {
     m_isInitialized = false;
 }
 
+void AudioNode::clearInternalState()
+{
+}
+
 void AudioNode::dispose()
 {
     ASSERT(isMainThread());
     ASSERT(context()->isGraphOwner());
 
     context()->removeChangedChannelCountMode(this);
     context()->removeAutomaticPullNode(this);
     context()->disposeOutputs(*this);
     for (unsigned i = 0; i < m_outputs.size(); ++i)
         output(i)->disconnectAll();
@@ skipping 366 matching lines @@
         // As far as JavaScript is concerned, our outputs must still appear to be connected.
         // But internally our outputs should be disabled from the inputs they're connected to.
         // disable() can recursively deref connections (and call disable()) down a whole chain of connected nodes.
 
         // FIXME: we special case the convolver and delay since they have a significant tail-time and shouldn't be disconnected simply
         // because they no longer have any input connections. This needs to be handled more generally where AudioNodes have
         // a tailTime attribute. Then the AudioNode only needs to remain "active" for tailTime seconds after there are no
         // longer any active connections.
         if (nodeType() != NodeTypeConvolver && nodeType() != NodeTypeDelay) {
             m_isDisabled = true;
+            // Resets internal states for future external data request. (i.e. Gain reduction)

[Raymond Toy, 2014/10/21 20:47:57]

I think I would remove this comment.  The comment for the clearInternalState
method should explain what is happening and why.

[hongchan, 2014/10/21 20:58:53]

Acknowledged.

+            if (nodeType() == NodeTypeDynamicsCompressor) {

[Raymond Toy, 2014/10/21 20:47:57]

This if test isn't needed.  Every node now has a clearInternalState method, and
the DynamicsCompressorNode has the right implementation to clear the internal
state.

[hongchan, 2014/10/21 20:58:53]

I agree, but this was what we talked about it before so I left it there.
Removing.

+                clearInternalState();
+            }
             for (unsigned i = 0; i < m_outputs.size(); ++i)
                 output(i)->disable();
         }
     }
 }
 
 void AudioNode::makeConnection()
 {
     atomicIncrement(&m_connectionRefCount);
 
@@ skipping 75 matching lines @@
 
 void AudioNode::updateChannelCountMode()
 {
     m_channelCountMode = m_newChannelCountMode;
     updateChannelsForInputs();
 }
 
 } // namespace blink
 
 #endif // ENABLE(WEB_AUDIO)