Compile shaders with the best profile available. Instead of always compiling D3D11 shaders with shader model 4, compile with the latest profile that the current feature level allows. BUG=angle:495 Change-Id: I478d3d4a1aadf24d893508eee1a8c11e501bc084 Reviewed-on: https://chromium-review.googlesource.com/190340 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>