The perf test initializes the compiler once and then translates the
same shader to HLSL, GLSL or ESSL repeatedly.

There are three variations of the test compiling different shaders.
One is a real-world shader.

BUG=angleproject:2267
TEST=angle_perftests

Change-Id: Ie07b67d7548d105c4c93dff3b6196233d83b5b8c
Reviewed-on: https://chromium-review.googlesource.com/883784Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>