Introduce Promise mapping to the IDL generator

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 18d30523fad4eef50394bc20bae123dba4888b14..e9d45ff6c31d90bc33b1d98bbb10e009afd694b2 100644
--- a/Source/bindings/v8/ScriptPromiseResolver.h
+++ b/Source/bindings/v8/ScriptPromiseResolver.h
@@ -33,6 +33,7 @@
 
 #include "bindings/v8/ScopedPersistent.h"
 #include "bindings/v8/ScriptObject.h"
+#include "bindings/v8/ScriptPromise.h"
 #include "bindings/v8/ScriptState.h"
 #include "bindings/v8/ScriptValue.h"
 #include "wtf/RefPtr.h"
@@ -83,10 +84,10 @@ public:
     //  - The resolver's resolved flag is not set.
     bool isPending() const;
 
-    ScriptObject promise()
+    ScriptPromise promise()
     {
         ASSERT(v8::Context::InContext());
-        return ScriptObject(ScriptState::current(), m_promise.newLocal(m_isolate));
+        return m_promise;
     }
 
     // Fulfill with a C++ object which can be converted to a v8 object by toV8.
@@ -110,7 +111,7 @@ private:
     void reject(v8::Handle<v8::Value>);
 
     v8::Isolate* m_isolate;
-    ScopedPersistent<v8::Object> m_promise;
+    ScriptPromise m_promise;

[haraken, 2013/09/03 17:03:07]

I still don't fully understand why this doesn't cause memory leaks nor leaks
between isolated worlds. Would you add a comment about it?

[yhirano, 2013/09/04 02:14:15]

Users of ScriptPromiseResolver should call detachPromise if they do  not need
the Promise object, as the class comment says. Otherwise a memory leak may be
introduced.
In a similar way, users of ScriptPromiseResolver should call fulfill / resolve /
reject if the operation completes or fails. Otherwise a memory leak may be
introduced.
Destroying the ScriptPromiseResolver object will detach the Promise and the
PromiseResolver objects.

In short, you have to call such methods manually if you hold
ScriptPromiseResolver as a member variable.

     ScopedPersistent<v8::Object> m_resolver;
     bool isPendingInternal() const;
 };