Implement suspend() and resume() for OfflineAudioContext

Source/modules/webaudio/AbstractAudioContext.h

Index: Source/modules/webaudio/AbstractAudioContext.h
diff --git a/Source/modules/webaudio/AbstractAudioContext.h b/Source/modules/webaudio/AbstractAudioContext.h
index 5994c223ef747ca2a9a8fd28584233c983c62d91..83c69e56acea96a8f568d0b62dd471cb52efdc3d 100644
--- a/Source/modules/webaudio/AbstractAudioContext.h
+++ b/Source/modules/webaudio/AbstractAudioContext.h
@@ -160,8 +160,12 @@ public:
     // Close
     virtual ScriptPromise closeContext(ScriptState*) = 0;
 
-    // Suspend/Resume
+    // We have 2 suspend methods for online and offline audio context with
+    // different method signature.

[Raymond Toy, 2015/07/15 20:59:13]

Maybe comment that the first can only be used for online and the second only for
offline?

[hongchan, 2015/07/15 23:24:22]

Done.

     virtual ScriptPromise suspendContext(ScriptState*) = 0;
+    virtual ScriptPromise suspendContext(ScriptState*, double) = 0;
+
+    // Resume
     virtual ScriptPromise resumeContext(ScriptState*) = 0;
 
     // When a source node has started processing and needs to be protected,
@@ -220,13 +224,14 @@ public:
     const AtomicString& interfaceName() const final;
     ExecutionContext* executionContext() const final;
 
-    DEFINE_ATTRIBUTE_EVENT_LISTENER(complete);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(statechange);
 
     void startRendering();
-    void fireCompletionEvent();
     void notifyStateChange();
 
+    // TODO(hongchan): move this to OfflineAudioContext.
+    AudioBuffer* renderTarget() const { return m_renderTarget.get(); }
+
     // A context is considered closed if:
     //  - closeContext() has been called.
     //  - it has been stopped by its execution context.
@@ -243,7 +248,7 @@ protected:
     virtual void didClose() {}
     void uninitialize();
 
-    RefPtrWillBeMember<ScriptPromiseResolver> m_offlineResolver;
+    // RefPtrWillBeMember<ScriptPromiseResolver> m_offlineResolver;
 
     // FIXME(dominicc): Move m_resumeResolvers to AudioContext, because only
     // it creates these Promises.
@@ -300,6 +305,8 @@ private:
     bool m_didInitializeContextGraphMutex;
     RefPtr<DeferredTaskHandler> m_deferredTaskHandler;
 
+    // For offline audio context.
+    // TODO(hongchan): move this to OfflineAudioContext class.
     Member<AudioBuffer> m_renderTarget;
 
     // The state of the AbstractAudioContext.