Implement suspend/resume for AudioContext

Source/modules/webaudio/AudioContext.h

Index: Source/modules/webaudio/AudioContext.h
diff --git a/Source/modules/webaudio/AudioContext.h b/Source/modules/webaudio/AudioContext.h
index 3377ce6497d2fc0b3bc80a36a085a82d99a24942..dda904f2b7a84daa3f33c740bad5151d800a934f 100644
--- a/Source/modules/webaudio/AudioContext.h
+++ b/Source/modules/webaudio/AudioContext.h
@@ -25,6 +25,8 @@
 #ifndef AudioContext_h
 #define AudioContext_h
 
+#include "bindings/core/v8/ScriptPromise.h"
+#include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "core/dom/ActiveDOMObject.h"
 #include "core/events/EventListener.h"
 #include "modules/EventTargetModules.h"
@@ -128,6 +130,10 @@ public:
     OscillatorNode* createOscillator();
     PeriodicWave* createPeriodicWave(Float32Array* real, Float32Array* imag, ExceptionState&);
 
+    // Pause/Resume
+    void suspendContext();
+    ScriptPromise resumeContext(ScriptState*);
+
     // When a source node has no more processing to do (has finished playing), then it tells the context to dereference it.
     void notifyNodeFinishedProcessing(AudioNode*);
 
@@ -166,6 +172,9 @@ public:
 
     unsigned connectionCount() const { return m_connectionCount; }
 
+    void resolvePromisesForResume();
+    void resolvePromisesForResumeOnMainThread();

[yhirano, 2014/10/08 01:12:14]

These function can be private.

+
     //
     // Thread Safety and Graph Locking:
     //
@@ -274,6 +283,13 @@ private:
     // AudioNode::breakConnection() when we remove an AudioNode from this.
     HeapVector<Member<AudioNode> > m_referencedNodes;
 
+    GC_PLUGIN_IGNORE("http://crbug.com/404527")
+    Vector<RefPtr<ScriptPromiseResolver> > m_resumePromises;
+    // True if we're in the process of resolving promises for resume().  Resolving can take some
+    // time and the audio context process loop is very fast, so we don't want to call resolve an
+    // excessive number of times.
+    bool m_isResolvingResumePromises;
+
     class AudioNodeDisposer {
     public:
         explicit AudioNodeDisposer(AudioNode& node) : m_node(node) { }