Add a cubemap array texture validation In ValidateTexture3DDestinationTarget(), Check if the cube map array extension is enabled if the TextureTarget is CubeMapArray. This helps catch the missing extension error earlier in ValidateES3TexImage3DParameters(), and the program won't crash when getTextureByType() is called later in ValidateES3TexImageParametersBase(). Bug: angleproject:6152 Change-Id: I2f1876f81688e7eef68bdf99276a3a9fafa224da Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3161440 Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Yuxin Hu <yuxinhu@google.com>