Fix Linux standalone compilation. simple_texture_2d, hello_triangle, stencil_operations, simple_texture_cubemap fail to compile after https://chromium-review.googlesource.com/342050. BUG=angleproject:1319 TEST=ninja -C out/Release all Change-Id: Ib70008036f8688b737f3f40b5224437a7afdea19 Reviewed-on: https://chromium-review.googlesource.com/346121 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Yuly Novikov <ynovikov@chromium.org>