Steps to reproduce:
1. Open user attached project
2. Enter play mode
3. Observe Game view only showing the white particles
4. Either:
a) Select "Main Camera" and enable HDR
b) Select "Main Camera", double click Target Texture to select the Render Texture and set Anti-Aliasing to anything above "None"
5. Observe Render Texture visible in Game view now producing visual distortion effect

Expected result: Distortion effect is applied regardless of HDR or Anti-aliasing being enabled or not.
Actual result: Effect is only applied when HDR or Anti-aliasing is enabled

Reproduced on 2017.1.0b4, 5.6.0p4, 5.5.3p3

Notes: On 5.5.3p3 toggling HDR did not activate the effect. Setting the Camera render mode to deferred or enabling anti-aliasing on render texture - did.
On 2017.1.0b4 toggling HDR did not activate the effect, nor did setting the render mode to deferred. Enabling anti-aliasing on RT did.