GL_OES_standard_derivatives, GL_EXT_shader_texture_lod and GL_EXT_frag_depth. TEST=conformance2/extensions/promoted-extensions-in-shaders TEST=conformance/glsl/misc/shader-with-dfdx.frag BUG=angleproject:1719 Change-Id: Ic0bd50c6a222940cc8de903f88f19a4f5ee08088 Reviewed-on: https://chromium-review.googlesource.com/476030 Commit-Queue: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org>
