Implement ScriptPromise and ScriptFunction

Source/bindings/v8/ScopedPersistent.h

Index: Source/bindings/v8/ScopedPersistent.h
diff --git a/Source/bindings/v8/ScopedPersistent.h b/Source/bindings/v8/ScopedPersistent.h
index faef97d9451ac5489b571cbc877a19310b130814..5264a91a9b8fa90deda90525803cfd3e97b4914b 100644
--- a/Source/bindings/v8/ScopedPersistent.h
+++ b/Source/bindings/v8/ScopedPersistent.h
@@ -64,6 +64,7 @@ public:
     }
 
     bool isEmpty() const { return m_handle.IsEmpty(); }
+    bool isWeak() const { return m_handle.IsWeak(); }
 
     void set(v8::Isolate* isolate, v8::Handle<T> handle)
     {
@@ -84,6 +85,12 @@ public:
         return m_handle == other.m_handle;
     }
 
+    template <class S>
+    bool operator==(const v8::Handle<S> other) const
+    {
+        return m_handle == other;
+    }
+
 private:
     // FIXME: This function does an unsafe handle access. Remove it.
     friend class V8AbstractEventListener;