Revert 233243 "Align the interface of TestHarness defined in gpu..."

Reverting because this patch caused the GPU bots to begin failing. The failures
may actually be legitimate, but we should determine if that's the case and fix
the failing tests before landing this patch again

> Align the interface of TestHarness defined in gpu_tests/webgl_conformance.py with that in third_party/webgl_conformance.
> 
> BUG=314997
> NOTRY=true
> 
> Review URL: https://codereview.chromium.org/58833003

TBR=jun.a.jiang@intel.com

Review URL: https://codereview.chromium.org/62573002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233299 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233299