Add an ASSERT about cross-world wrapper leakage into ScriptValue

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 20314b05b3e8eea11034d9fa16ded49ebd959471..521d326a98a640068d1185d773681051d4b11cdc 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -2286,10 +2286,9 @@ private:
     virtual ScriptValue call(ScriptValue value) OVERRIDE
     {
         v8::Local<v8::Value> v8Value = value.v8Value();
-        v8::Isolate* isolate = value.isolate();
         ASSERT(v8Value->IsNumber());
         int intValue = v8Value.As<v8::Integer>()->Value();
-        ScriptValue result  = ScriptValue(value.scriptState(), v8::Integer::New(isolate, intValue + 1));
+        ScriptValue result  = ScriptValue(ScriptState::current(isolate()), v8::Integer::New(isolate(), intValue + 1));
         return result;
     }
 };