JS -> Native Functional Call Performance

Hi,

In my use case, I'm binding WebGL calls to their OpenGL counterpart in Java. I'm encountering some performance issues that I narrowed down to the time it takes to call a native function from JavaScript.

My test case is:

```
v8object.registerJavaMethod(this, "profile", "profile", new Class[] { int.class });
public void profile(int time) {

}
```

In JavaScript:

```
var time = 0;
for (var i = 0; i < 100; i++) {
let t = performance.now();
profile(i);
time += (performance.now() - t);
}

time /= 100;
```

My device is a Nexus 6P

performance.now is another native hook, so that's adding a bit to the time calculated I'm sure but the end result is the average time to call a native function according to this test is 0.4981, which at half a millisecond is already causing performance issues even just drawing a few objects in my GL scene.

I'd be very grateful to hear your thoughts on this and if there is anything I can do to speed things up.