How to reproduce:

1. Open attached project (35518 substance ram.zip)
2. Build to iOS and run
- Once run, there should be two spinning cubes
- Tapping the screen once causes a .jpg material to load
- Tapping the screen again causes a .raw material to load
- Both materials are identical, except for the source texture format
3. Open the Profiler window and profile the device
4. Tap the screen once
- Note how the memory usage increases by a tiny bit
5. Tap the screen again
- Note how the memory usage increases by about 4 megabytes
- The memory usage shouldn't increase at all after the first tap
- Reproduced in Version 5.4.0b1 (3137382c8e08), Version 5.3.1p2 (49544457ab1d), Version 5.3.1f1 (3b3e8231502f), Version 5.2.4f1 (98095704e6fe) on an iPad Air 2 (iOS8.1)
- Not reproducible in the Editor