Revert "Generates GPU driver tags for WebGL expectations"

This reverts commit 60abae9cc084a076575c96409fc029194f42c2ba.

Reason for revert: caused flaky Mac WebGL conformance failures in Issue 979391.

Original change's description:
> Generates GPU driver tags for WebGL expectations
> 
> For WebGL conformance test, we can specify some conditions to limit the
> test environment that one test case may fail. But these conditions don't
> include graphics driver information. By this patch, the WebGL test
> framework can generate driver tags based on the vendor and version of
> the graphics driver of current system for the expectations file. The
> format of driver tag is as below:
> crbug.com/123 [ linux mesa_lt_18.0.5 ] abc.html [ Failure ]
> 
> When adding or removing driver tags in the expectatioins file, it's also
> necessary to modify the list of available driver tags in the header of
> webgl_conformance_integration_test.py.
> 
> Bug: 957515
> Change-Id: I29835cae0b042cd86eb4fa438f60803e371d8d1a
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1647464
> Commit-Queue: Lin Sun <lin.sun@intel.com>
> Reviewed-by: Kenneth Russell <kbr@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#672596}

TBR=kbr@chromium.org,lin.sun@intel.com,rmhasan@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 957515, 979391
Change-Id: I9fb36eae1b6baac680eaa124487603fcd4ee8d1a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1681305
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#673205}
7 files changed