Support glCopyTex[Sub]Image to LUMA formats on the core profile.

BUG=577144
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2027703003
Cr-Commit-Position: refs/heads/master@{#399545}
diff --git a/gpu/command_buffer/service/BUILD.gn b/gpu/command_buffer/service/BUILD.gn
index 41da83d..c19fa7e7 100644
--- a/gpu/command_buffer/service/BUILD.gn
+++ b/gpu/command_buffer/service/BUILD.gn
@@ -56,6 +56,8 @@
     "gl_utils.h",
     "gles2_cmd_clear_framebuffer.cc",
     "gles2_cmd_clear_framebuffer.h",
+    "gles2_cmd_copy_tex_image.cc",
+    "gles2_cmd_copy_tex_image.h",
     "gles2_cmd_copy_texture_chromium.cc",
     "gles2_cmd_copy_texture_chromium.h",
     "gles2_cmd_decoder.cc",