As a follow-on to removing security manager support, we are removing all references to the terminally deprecated AccessController and AccessControlConext classes. This is tracked by JDK-8342993.

The Java code passes an AccessControlConext instance to the native JSObject code, which stores it in the object so that it can later pass it back to the Utilities::fwkInvokeWithContext Java method via a JNI upcall. The native WebKit otherwise does not use the AccessControlConext object. Since it is already treated as an opaque object by the native code, the easiest path to eliminating the references to AccessControlConext is to change the method signatures to pass an Object rather than AccessControlConext. This has two related advantages:

1. It will minimize the changes to native WebKit JNI code.
2. It will allow us to keep the native code identical between mainline jfx24 and earlier releases (e.g., jfx23u, jfx21u, etc), since earlier releases still need to be able to run with a security manager.

This bug fix needs to go in ahead of the fix for JDK-8342993 and should be backported to all earlier code lines (whereas none of the other SM follow-up fixes can be backported).