Introduce KeepAliveWhilePending to ScriptPromiseResolverWithContext.

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 4fc434ecc088a1d7302354294bba3a8e648b1db2..803f2ec7eee048a49d49a7293c1dfd3e71a5bb14 100644
--- a/Source/modules/webmidi/MIDIAccessInitializer.h
+++ b/Source/modules/webmidi/MIDIAccessInitializer.h
@@ -6,10 +6,13 @@
 #define MIDIAccessInitializer_h
 
 #include "bindings/v8/ScriptPromise.h"
+#include "core/dom/AsyncInitializerResolver.h"
 #include "modules/webmidi/MIDIAccessor.h"
 #include "modules/webmidi/MIDIAccessorClient.h"
 #include "modules/webmidi/MIDIOptions.h"
+#include "modules/webmidi/MIDIPort.h"
 #include "wtf/OwnPtr.h"
+#include "wtf/Vector.h"
 
 namespace WebCore {
 
@@ -19,16 +22,29 @@ class ScriptPromiseResolverWithContext;
 
 class MIDIAccessInitializer : public MIDIAccessorClient {
 public:
-    static PassOwnPtr<MIDIAccessInitializer> create(const MIDIOptions& options, MIDIAccess* access)
+    struct PortDescriptor {
+        String id;
+        String manufacturer;
+        String name;
+        MIDIPort::MIDIPortTypeCode type;
+        String version;
+
+        PortDescriptor(const String& id, const String& manufacturer, const String& name, MIDIPort::MIDIPortTypeCode type, const String& version)
+            : id(id)
+            , manufacturer(manufacturer)
+            , name(name)
+            , type(type)
+            , version(version) { }
+    };
+
+    static PassOwnPtr<MIDIAccessInitializer> create(const MIDIOptions& options)
     {
-        return adoptPtr(new MIDIAccessInitializer(options, access));
+        return adoptPtr(new MIDIAccessInitializer(options));
     }
     virtual ~MIDIAccessInitializer();
 
-    ScriptPromise initialize(ScriptState*);
-    void cancel();
-
-    bool hasPendingActivity() const { return m_state == Requesting; }
+    void start(AsyncInitializerResolver<MIDIAccessInitializer>*);
+    void contextDestroyed() { cancel(); }
 
     // MIDIAccessorClient
     virtual void didAddInputPort(const String& id, const String& manufacturer, const String& name, const String& version) OVERRIDE;
@@ -40,27 +56,16 @@ public:
     SecurityOrigin* securityOrigin() const;
 
 private:
-    class PostAction;
-    enum State {
-        Requesting,
-        Resolved,
-        Stopped,
-    };
-
-    MIDIAccessInitializer(const MIDIOptions&, MIDIAccess*);
-
-    ExecutionContext* executionContext() const;
+    explicit MIDIAccessInitializer(const MIDIOptions&);
+    void cancel();
     void permissionDenied();
-    void doPostAction(State);
+    ExecutionContext* executionContext() const;
 
-    State m_state;
-    WeakPtrFactory<MIDIAccessInitializer> m_weakPtrFactory;
-    RefPtr<ScriptPromiseResolverWithContext> m_resolver;
+    AsyncInitializerResolver<MIDIAccessInitializer>* m_resolver;
     OwnPtr<MIDIAccessor> m_accessor;
     MIDIOptions m_options;
     bool m_sysexEnabled;
-    // m_access has this object, so it's safe to have the raw pointer.
-    MIDIAccess* m_access;
+    Vector<PortDescriptor> m_portDescriptors;
 };
 
 } // namespace WebCore