Make chrome GN build work in component mode.

content/common/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/features.gni")
 import("//build/config/ui.gni")
 import("//content/common/common.gni")
 import("//mojo/public/tools/bindings/mojom.gni")
 
 source_set("common") {
-  # Only targets in the content tree can depend directly on this target.
-  visibility = [ "//content/*" ]
+  # Only the public target should depend on this. All other targets (even
+  # internal content ones) should depend on the public one.
+  visibility = [ "//content/public/common:common_sources" ]
 
   sources = rebase_path(content_common_gypi_values.private_common_sources,
                         ".", "//content")
 
   forward_dependent_configs_from = [
     "//gpu/command_buffer/common",
     "//third_party/WebKit/public:blink_headers",
   ]
 
   configs += [
@@ skipping 21 matching lines @@
 
   if (!is_ios) {
     deps += [
       "//cc",
       "//ipc",
       "//ipc/mojo",
       # TODO: the dependency on gl_in_process_context should be decoupled from
       # content and moved to android_webview. See crbug.com/365797.
       "//gpu/command_buffer/client:gl_in_process_context",
       "//gpu/command_buffer/client:gles2_c_lib",
+      "//gpu/command_buffer/client:gles2_cmd_helper",
       "//gpu/command_buffer/client:gles2_implementation",
       "//gpu/command_buffer/service",
       "//gpu/ipc",
       "//gpu/skia_bindings",
       "//media",
       "//media:shared_memory_support",
       "//mojo/environment:chromium",
       "//mojo/public/interfaces/application",
       "//mojo/system",
       "//sandbox",
@@ skipping 216 matching lines @@
 
 mojom("mojo_bindings") {
   sources = [
     "render_frame_setup.mojom",
   ]
 
   deps = [
     "//mojo/public/interfaces/application:application",
   ]
 }