Fix bug loading untrusted applications that have not been sized.
Fixed a security violation trying to access untrusted content. The problem happened in doScaleContent() when the loaded content had not been sized yet. The fall back is to check the class type of the content, but the SWFLoader did not have access to the content. The security violation was caught and the FlexLoader size is set when it shouldn't be. The problem is solved by checking access rights before accessing the content and not generating an exception.