*re-land with Linux fixes, and fix for locations*

This built-in uniform wasn't being collected in VariableInfo.cpp.
Also remove the existing workaround for D3D gl_DepthRange
collection.

BUG=angleproject:991
BUG=478570

Change-Id: Iba84651bfc58f82fd4ce039421874f561f83c348
Reviewed-on: https://chromium-review.googlesource.com/268840Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>