Fix V4L2VideoEncodeAccelerator is not enabled in GN build

media/gpu/ipc/service/BUILD.gn

 # Copyright 2016 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("service") {
   visibility = [
     "//media/*",
     "//content/gpu/*",
     "//content/public/gpu/*",
     "//services/ui/gpu/*",
@@ skipping 20 matching lines @@
     "//ipc",
     "//media",
     "//media/gpu",
   ]
   deps = [
     "//gpu/ipc/service",
     "//media/gpu/ipc/common",
     "//third_party/mesa:mesa_headers",
   ]
 
+  public_configs = [ "//media/gpu:gpu_config" ]

[wuchengli, 2016/07/12 11:39:51]

s/public_configs/configs/. We don't need to propagate this to the dependents of
this target.

Please also help change public_configs to configs in
media/gpu/ipc/client/BUILD.gn.

[wuchengli, 2016/07/12 15:00:55]

I found why media/gpu/ipc/client/BUILD.gn used public_configs.
bpf_gpu_policy_linux.cc needs USE_LIBV4L2 and it depends on
media/gpu/ipc/client. No need to change media/gpu/ipc/client/BUILD.gn.

[henryhsu, 2016/07/13 03:29:59]

Done.

+
   if (is_chromeos && current_cpu != "arm") {
     configs += [ "//third_party/libva:libva_config" ]
   }
 
   if (is_win) {
     configs += [ "//build/config/compiler:no_size_t_to_int_warning" ]
   }
 
   if (is_mac) {
     deps += [ "//third_party/webrtc/common_video:common_video" ]
   }
 }