See dEQP-GLES3.functional.fbo.color.repeated_clear.sample.tex2d.rgba8

This test uses ClearRenderTargetView to clear various FBO textures,
but it does not seem to work correctly on my Nvidia configuration.
It has been reported to Nvidia. It also seems to fail on Intel.

Current GPU: NVIDIA GeForce GTX 660
Current Driver: 10.18.13.5598 (9-13-2015)
Works on Desktop OpenGL back-end, also on AMD R5230

BUG=angleproject:1305

Change-Id: I4b53b7376faf71f234d05c90f4fb55462de23e36
Reviewed-on: https://chromium-review.googlesource.com/314304Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>