Revert "Support GL_ETC1_RGB8_OES in the OpenGL renderer." Failing some ES2 dEQP tests. This reverts commit 4aba0b90ec3d2dcd550ed4111f5739191f022028. Change-Id: Ie39055872d25bce0f387e9e983ebab648c0493f0 Reviewed-on: https://chromium-review.googlesource.com/298972 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>