I've found the answer for desktops, but I could not find anything for Android/iOS (assume I can use up to OpenGL ES 3.0). So this is the same question for mobile devices: Is it possible to get the total memory in bytes used by OpenGL by my application programatically?
Note: I am OK with a non-universal solution (AFAIK universal solution does not exists), but something that works at least on popular devices (iOS/Snapdragon/..)