Add a perf test for draw calls with texture changes. This perf test highlights the performance hotspots with State::syncProgramTextures. Also includes a fix to the perf test runner script. Bug: angleproject:2763 Change-Id: I69ffa0cc0d5e023944495b7a1c844770a54f7ddc Reviewed-on: https://chromium-review.googlesource.com/1166041 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org>