Add missing files/deps/defines

gpu/command_buffer/common/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 source_set("common") {
   sources = [
     "bitfield_helpers.h",
     "buffer.cc",
     "buffer.h",
     "capabilities.cc",
     "capabilities.h",
     "cmd_buffer_common.cc",
     "cmd_buffer_common.h",
     "command_buffer.h",
     "constants.h",
     "debug_marker_manager.cc",
     "debug_marker_manager.h",
     "gles2_cmd_format.cc",
     "gles2_cmd_format.h",
     "gles2_cmd_format.h",
     "gles2_cmd_format_autogen.h",
     "gles2_cmd_ids.h",
     "gles2_cmd_ids_autogen.h",
-    "gles2_cmd_utils.cc",
-    "gles2_cmd_utils.h",
-    "gles2_utils_export.h",
     "id_allocator.cc",
     "id_allocator.h",
     "mailbox.cc",
     "mailbox.h",
     "mailbox_holder.cc",
     "mailbox_holder.h",
     "thread_local.h",
     "time.h",
   ]
 
-  all_dependent_configs = [ "//third_party/khronos:khronos_headers" ]
+  defines = [ "GPU_IMPLEMENTATION" ]
+
+  deps = [
+    ":gles2_utils",
+    "//base",
+  ]
+}
+
+component("gles2_utils") {
+  sources = [
+    "gles2_cmd_utils.cc",
+    "gles2_cmd_utils.h",
+    "gles2_utils_export.h",
+  ]
+
+  defines = [ "GLES2_UTILS_IMPLEMENTATION" ]
 
   deps = [
     "//base",
   ]
+
+  all_dependent_configs = [ "//third_party/khronos:khronos_headers" ]
 }