Split ANGLEPerfTest into a Render and basic test. The basic test we can use for perf testing internal classes with mocks. The render tests are more specific to doing draw calls. BUG=angleproject:956 Change-Id: Iade393facc30c8d7288b1b94a159ce3afe993021 Reviewed-on: https://chromium-review.googlesource.com/262775 Reviewed-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>