Split "Online" and "Offline" AudioContext processing

Source/modules/webaudio/GainNode.cpp

Index: Source/modules/webaudio/GainNode.cpp
diff --git a/Source/modules/webaudio/GainNode.cpp b/Source/modules/webaudio/GainNode.cpp
index 8b2067719e8b9308e86b54c4fa6dcd2493e032f3..b61c4759efd1cae257c90c481998b6be9ac50e1c 100644
--- a/Source/modules/webaudio/GainNode.cpp
+++ b/Source/modules/webaudio/GainNode.cpp
@@ -111,14 +111,14 @@ void GainHandler::checkNumberOfChannelsForInput(AudioNodeInput* input)
 
 // ----------------------------------------------------------------
 
-GainNode::GainNode(AudioContext& context, float sampleRate)
+GainNode::GainNode(AbstractAudioContext& context, float sampleRate)
     : AudioNode(context)
     , m_gain(AudioParam::create(context, 1.0))
 {
     setHandler(GainHandler::create(*this, sampleRate, m_gain->handler()));
 }
 
-GainNode* GainNode::create(AudioContext& context, float sampleRate)
+GainNode* GainNode::create(AbstractAudioContext& context, float sampleRate)
 {
     return new GainNode(context, sampleRate);
 }