Oilpan: cancel MIDI permission request when prefinalizing

Source/modules/webmidi/MIDIAccessInitializer.h

Index: Source/modules/webmidi/MIDIAccessInitializer.h
diff --git a/Source/modules/webmidi/MIDIAccessInitializer.h b/Source/modules/webmidi/MIDIAccessInitializer.h
index 6a26940101cb8511da0c1b92cc19ec0ab94b30c4..1aeee6401ea6bbee077a8380de545ff69f531a46 100644
--- a/Source/modules/webmidi/MIDIAccessInitializer.h
+++ b/Source/modules/webmidi/MIDIAccessInitializer.h
@@ -19,6 +19,9 @@ class MIDIOptions;
 class ScriptState;
 
 class MIDIAccessInitializer : public ScriptPromiseResolver, public MIDIAccessorClient {
+#if ENABLE(OILPAN)
+    USING_PRE_FINALIZER(MIDIAccessInitializer, dispose);

[haraken, 2014/12/19 03:47:16]

Just to confirm: The reason we cannot use WeakMember (i.e., have MIDIController
hold WeakMember<MIDIAccessInitializer>) is that the weak processing does not run
when the MIDIController and the MIDIAccessInitializer die together, right?
MIDIController always needs to cancel the permission request when the
MIDIAccessInitializer dies (regardless of whether the MIDIController dies at the
same time or not). Thus we need to use a pre-finalizer. Am I understanding
correctly?

+#endif
 public:
     struct PortDescriptor {
         String id;
@@ -59,15 +62,15 @@ public:
     SecurityOrigin* securityOrigin() const;
 
 private:
-    ScriptPromise start();
-
     MIDIAccessInitializer(ScriptState*, const MIDIOptions&);
 
     ExecutionContext* executionContext() const;
+    ScriptPromise start();
+    void dispose();
 
     OwnPtr<MIDIAccessor> m_accessor;
-    bool m_requestSysex;
     Vector<PortDescriptor> m_portDescriptors;
+    bool m_requestSysex;
 };
 
 } // namespace blink