nsIXPConnect in Firefox 2.0

 Preconfigure XPCNativeWrapper automation so that when a scripted
 caller whose filename starts with filenamePrefix accesses a wrapped
 native that is not flagged as "system", the wrapped native will be
 automatically wrapped with an XPCNativeWrapper.

 @param aFilenamePrefix the UTF-8 filename prefix to match, which
                        should end with a slash (/) character

 This only succeeds if the JSObject is a nsIXPConnectWrappedNative.
 A new wrapper is *never* constructed.

 This only succeeds if the native object is already wrapped by xpconnect.
 A new wrapper is *never* constructed.

 Restore an old prototype for wrapped natives of type
 aClassInfo. This should be used only when restoring an old
 scope into a state close to where it was prior to
 being reinitialized.

 The security manager to use when the current JSContext has no security
 manager.

 Set fallback JSContext to use when xpconnect can't find an appropriate
 context to use to execute JavaScript.

 NOTE: This method is DEPRECATED. 
       Use nsIThreadJSContextStack::safeJSContext instead.

 XPConnect builds internal objects that parallel, and are one-to-one with,
 the JSContexts in the JSRuntime. It builds these objects as needed.
 This method tells XPConnect to resynchronize its representations with the
 list of JSContexts currently 'alive' in the JSRuntime. This allows it
 to cleanup any representations of JSContexts that are no longer valid.

 wrapJS will yield a new or previously existing xpcom interface pointer
 to represent the JSObject passed in.

 This method now correctly deals with cases where the passed in JSObject
 already has an associated xpcom interface for the cases:
  1) The JSObject has already been wrapped as a nsIXPConnectWrappedJS.
  2) The JSObject is in fact a nsIXPConnectWrappedNative and thus already
     has an underlying xpcom object.
  3) The JSObject is of a jsclass which supports getting the nsISupports
     from the JSObject directly. This is used for idlc style objects
     (e.g. DOM objects).

 It *might* be possible to QueryInterface the resulting interface pointer
 to nsIXPConnectWrappedJS.

 Returns:
   success:
     NS_OK
    failure:
       NS_ERROR_XPC_BAD_CONVERT_JS
       NS_ERROR_FAILURE

 wrapJSAggregatedToNative is just like wrapJS except it is used in cases
 where the JSObject is also aggregated to some native xpcom Object.
 At present XBL is the only system that might want to do this.

 XXX write more!

 Returns:
   success:
     NS_OK
    failure:
       NS_ERROR_XPC_BAD_CONVERT_JS
       NS_ERROR_FAILURE

 wrapNative will create a new JSObject or return an existing one.

 The JSObject is returned inside a refcounted nsIXPConnectJSObjectHolder.
 As long as this holder is held the JSObject will be protected from
 collection by JavaScript's garbage collector. It is a good idea to
 transfer the JSObject to some equally protected place before releasing
 the holder (i.e. use JS_SetProperty to make this object a property of
 some other JSObject).

 This method now correctly deals with cases where the passed in xpcom
 object already has an associated JSObject for the cases:
  1) The xpcom object has already been wrapped for use in the same scope
     as an nsIXPConnectWrappedNative.
  2) The xpcom object is in fact a nsIXPConnectWrappedJS and thus already
     has an underlying JSObject.
  3) The xpcom object implements nsIScriptObjectOwner; i.e. is an idlc
     style DOM object for which we can call GetScriptObject to get the
     JSObject it uses to represent itself into JavaScript.

 It *might* be possible to QueryInterface the nsIXPConnectJSObjectHolder
 returned by the method into a nsIXPConnectWrappedNative or a
 nsIXPConnectWrappedJS.

 This method will never wrap the JSObject involved in an
 XPCNativeWrapper before returning.

 Returns:
    success:
       NS_OK
    failure:
       NS_ERROR_XPC_BAD_CONVERT_NATIVE
       NS_ERROR_XPC_CANT_GET_JSOBJECT_OF_DOM_OBJECT
       NS_ERROR_FAILURE