ScriptPromise implementation for V8 Promises

Source/bindings/v8/ScriptPromiseResolver.h

Index: Source/bindings/v8/ScriptPromiseResolver.h
diff --git a/Source/bindings/v8/ScriptPromiseResolver.h b/Source/bindings/v8/ScriptPromiseResolver.h
index 200638e468e85b564677987c725f15e79764ff16..5137eaac092d0cd37e4c25077a3111bc5a7bdce8 100644
--- a/Source/bindings/v8/ScriptPromiseResolver.h
+++ b/Source/bindings/v8/ScriptPromiseResolver.h
@@ -51,7 +51,7 @@ class ExecutionContext;
 // ScriptPromiseResolver holds a PromiseResolver.
 // Here is a typical usage:
 //  1. Create a ScriptPromiseResolver.
-//  2. Pass the promise object of the holder to a JavaScript program
+//  2. Pass the associated promise object to a JavaScript program
 //     (such as XMLHttpRequest return value).
 //  3. Call resolve or reject when the operation completes or
 //     the operation fails respectively.
@@ -63,7 +63,10 @@ class ExecutionContext;
 // To prevent memory leaks, you should release the reference manually
 // by calling resolve or reject.
 // Destroying the object will also release the reference.
-//
+// Note that ScriptPromiseResolver::promise returns an empty value when the
+// resolver is already resolved or rejected. If you want to resolve a resolver
+// immediately and return the associated promise, you should get the promise
+// before resolving.
 class ScriptPromiseResolver : public RefCounted<ScriptPromiseResolver> {
     WTF_MAKE_NONCOPYABLE(ScriptPromiseResolver);
 public:
@@ -76,14 +79,10 @@ public:
     // entering a v8 context.
     ~ScriptPromiseResolver();
 
-    // Return true if the promise object is in pending state.
-    bool isPending() const;
-
-    ScriptPromise promise()
-    {
-        ASSERT(m_promise.isolate()->InContext());
-        return m_promise;
-    }
+    // Returns the underlying Promise.
+    // Note that the underlying Promise is cleared when |resolve| or |reject|
+    // is called.
+    ScriptPromise promise();
 
     // To use following template methods, T must be a DOM class.
 
@@ -141,7 +140,10 @@ private:
     void reject(v8::Handle<v8::Value>);
 
     v8::Isolate* m_isolate;
+    // Used when scriptPromiseOnV8Promise is disabled.
     ScriptPromise m_promise;
+    // Used when scriptPromiseOnV8Promise is enabled.
+    ScriptValue m_resolver;
 };
 
 template<typename T>