Add GPU command buffer sevice and protobuf to GN build

ui/gl/BUILD.gn

 # Copyright 2014 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.
 
 import("//build/config/ui.gni")
 
 gl_binding_output_dir = target_gen_dir
 
 config("gl_config") {
   if (use_x11) {
     defines = [ "GL_GLEXT_PROTOTYPES" ]
   }
+
+  # TODO(brettw) this should be removed and the the files using the generated
+  # GL bindings should use the path inside the gen directory.
+  include_dirs = [ gl_binding_output_dir ]
 }
 
 component("gl") {
   output_name = "gl_wrapper"  # Avoid colliding with OS X"s libGL.dylib.
 
   sources = [
     "android/gl_jni_registrar.cc",
     "android/gl_jni_registrar.h",
     "android/scoped_java_surface.cc",
     "android/scoped_java_surface.h",
@@ skipping 209 matching lines @@
     ]
   }
 
   # TODO(GYP) enable this dependency once its written.
   #if (is_android && !android_webview_build) {
   #  deps += [ "//ui/android:ui_java" ]
   #}
 }
 
 action("generate_gl_bindings") {
+  visibility = ":*"  # Only targets in this file can see this.
+
   script = "generate_bindings.py"
 
   # TODO(brettw) make this dynamic. The GYP version calls "generate_bindings.py
   # --inputs" to get the list here. What should happen is that the script
   # should generate a .d file, which we should declare here. That will
   # eliminate the need bot both hardcoding the list here or calling the script
   # during GN-time.
   source_prereqs = [
     "EGL/eglextchromium.h",
     "GL/glextchromium.h",
@@ skipping 28 matching lines @@
     "$gl_binding_output_dir/gl_mock_autogen_gl.h",
   ]
 
   args = [
     "--header-paths=" +
         rebase_path("//third_party/khronos", root_build_dir) + ":" +
         rebase_path("//third_party/mesa/src/include", root_build_dir),
     rebase_path(gl_binding_output_dir, root_build_dir),
   ]
 }