New Anti-Aliasing + Depth of Field effects on camera cause UI images in the vicinity to momentarily swap with what looks like a scrambled font texture when UI element is moved rapidly over a terrain using multiple textures with Normal Maps when in full-screen (player) or free aspect (editor) mode.

Repro steps: (editor)
1. Open Level_01 from attached project.
2. Ensure game is set to "Free Aspect" and "Maximize on Play".
3. Play game, press "B" to open build menu, and rapidly and randomly press the alpha-numeric keys 1-4.
4. Observe UI displaying visual glitch periodically.

Repro steps: (player)
Get player from: https://drive.google.com/a/unity3d.com/file/d/0B4iLDbefUqzANUM0VlN5amNIUWM/view?usp=sharing
(Fogbugs issue not accepting attachment of files, couldn't upload...)
1. Extract project and open executable.
2. Make sure it's playing in full-screen mode (resolution doesn't matter).
3. In game, press "B" to open build menu, then rapidly and randomly press between 1-4 on the keyboard.
4. Observe visual glitch.

Expected outcome: no visual UI glitch.

Notes:
- Anti-aliasing being on top of depth of field seems to cause the issue more, through it appears regardless of the order.
- Looking up in the sky so the UI is not over the terrain does not cause the issue to appear.
- Not a regression; new feature, issue appears in 5.4.0b1.