Store MutationObserver callback in a hidden property for V8

Store MutationObserver callback in a hidden property for V8
https://bugs.webkit.org/show_bug.cgi?id=102555

Patch by Elliott Sprehn <esprehn@chromium.org> on 2012-11-20
Reviewed by Adam Barth.

.:

Test for reference cycle leaks with mutation observers. There doesn't seem
to be a way to check this for v8, but if you manually run you can see if it
leaks observers.

* ManualTests/leak-cycle-observer-wrapper.html: Added.

Source/WebCore:

To prevent circular reference leaks we should store the MutationObserver
callback in a hidden property on the wrapper of the observer.

This is done by extending the code generator to support a new owner
argument to ::create() that lets you set the owner of the callback where
the hidden property should be stored.

Test: ManualTests/leak-cycle-observer-wrapper.html

* bindings/scripts/CodeGeneratorV8.pm:
(GenerateCallbackHeader):
(GenerateCallbackImplementation):
* bindings/scripts/test/V8/V8TestCallback.cpp: rebaselined.
* bindings/scripts/test/V8/V8TestCallback.h: rebaselined.
* bindings/v8/V8HiddenPropertyName.h:
* bindings/v8/custom/V8MutationObserverCustom.cpp:
(WebCore::V8MutationObserver::constructorCallback):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@135305 268f45cc-cd09-0410-ab3c-d52691b4dbfc