Implement suspend() and resume() for OfflineAudioContext

Source/modules/webaudio/AudioNode.h

 /*
  * 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 89 matching lines @@
     virtual void dispose();
 
     // node() returns a valid object until dispose() is called.  This returns
     // nullptr after dispose().  We must not call node() in an audio rendering
     // thread.
     AudioNode* node() const;
     // context() returns a valid object until the AbstractAudioContext dies, and returns
     // nullptr otherwise.  This always returns a valid object in an audio
     // rendering thread, and inside dispose().  We must not call context() in
     // the destructor.
-    AbstractAudioContext* context() const;
+    virtual AbstractAudioContext* context() const;
     void clearContext() { m_context = nullptr; }
 
     enum ChannelCountMode {
         Max,
         ClampedMax,
         Explicit
     };
 
     NodeType nodeType() const { return m_nodeType; }
     String nodeTypeName() const;
@@ skipping 101 matching lines @@
     void addOutput(unsigned numberOfChannels);
 
     // Called by processIfNecessary() to cause all parts of the rendering graph connected to us to process.
     // Each rendering quantum, the audio data for each of the AudioNode's inputs will be available after this method is called.
     // Called from context's audio thread.
     virtual void pullInputs(size_t framesToProcess);
 
     // Force all inputs to take any channel interpretation changes into account.
     void updateChannelsForInputs();
 
+    // This raw pointer is safe because this is cleared for all of live
+    // AudioHandlers when the AbstractAudioContext dies.  Do not access m_context
+    // directly, use context() instead.
+    GC_PLUGIN_IGNORE("http://crbug.com/404527")
+    AbstractAudioContext* m_context;
+
 private:
     void setNodeType(NodeType);
 
     volatile bool m_isInitialized;
     NodeType m_nodeType;
 
     // The owner AudioNode.  This raw pointer is safe because dispose() is
     // called before the AudioNode death, and it clears m_node.  Do not access
     // m_node directly, use node() instead.
     GC_PLUGIN_IGNORE("http://crbug.com/404527")
     AudioNode* m_node;
 
-    // This raw pointer is safe because this is cleared for all of live
-    // AudioHandlers when the AbstractAudioContext dies.  Do not access m_context
-    // directly, use context() instead.
-    GC_PLUGIN_IGNORE("http://crbug.com/404527")
-    AbstractAudioContext* m_context;
-
     float m_sampleRate;
     Vector<OwnPtr<AudioNodeInput>> m_inputs;
     Vector<OwnPtr<AudioNodeOutput>> m_outputs;
 
     double m_lastProcessingTime;
     double m_lastNonSilentTime;
 
     volatile int m_connectionRefCount;
 
     bool m_isDisabled;
@@ skipping 70 matching lines @@
     HeapVector<Member<HeapHashSet<Member<AudioNode>>>> m_connectedNodes;
     // Represents audio node graph with Oilpan references. N-th HeapHashSet
     // represents a set of AudioParam objects connected to this AudioNode's N-th
     // output.
     HeapVector<Member<HeapHashSet<Member<AudioParam>>>> m_connectedParams;
 };
 
 } // namespace blink
 
 #endif // AudioNode_h