Split "Online" and "Offline" AudioContext processing

Source/modules/webaudio/ConvolverNode.h

Index: Source/modules/webaudio/ConvolverNode.h
diff --git a/Source/modules/webaudio/ConvolverNode.h b/Source/modules/webaudio/ConvolverNode.h
index 81437670715eb45deaf3ff978aedc4e0e4e09ead..a9337ed62947eb8a9c83004f2e440472031d523e 100644
--- a/Source/modules/webaudio/ConvolverNode.h
+++ b/Source/modules/webaudio/ConvolverNode.h
@@ -75,7 +75,7 @@ private:
 class MODULES_EXPORT ConvolverNode final : public AudioNode {
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static ConvolverNode* create(AudioContext&, float sampleRate);
+    static ConvolverNode* create(AbstractAudioContext&, float sampleRate);
 
     AudioBuffer* buffer() const;
     void setBuffer(AudioBuffer*, ExceptionState&);
@@ -83,7 +83,7 @@ public:
     void setNormalize(bool);
 
 private:
-    ConvolverNode(AudioContext&, float sampleRate);
+    ConvolverNode(AbstractAudioContext&, float sampleRate);
     ConvolverHandler& convolverHandler() const;
 
     // TODO(tkent): Use FRIEND_TEST macro provided by gtest_prod.h