Although I am now a Coloradoan, I formerly was a Texas resident, still spend a good deal of my time in Texas, and have held a Texas CHL for 16 years.
If you had your OK handgun license, which is recognized by Texas, you are required to inform LE upon a traffic stop if you are carrying. You are not REQUIRED to inform if you are not a licensee. You would want to inform if the handgun was in the same console/glove box where you keep your registration & insurance card- which is probably not a good idea anyway.
This seems a bit strange but that is due to the fact that the change in the law (in 2007 - I believe it was) decriminalizing the UNLICENSED carry of a handgun not in plain view inside of YOUR vehicle passenger compartment is not related to the pre-existing CHL law requiring you to notify LEO's.