Eliminate remaining ../ header includes

chrome/browser/chromeos/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("//extensions/features/features.gni")
 import("//media/media_options.gni")
 import("//printing/features/features.gni")
 import("//third_party/protobuf/proto_library.gni")
@@ skipping 1832 matching lines @@
     "//components/policy:generated",
     "//components/resources",
     "//components/sync",
     "//components/variations:test_support",
     "//crypto:platform",
     "//dbus",
     "//mojo/public/cpp/system:system",
     "//skia",
     "//testing/gmock",
     "//testing/gtest",
+    "//third_party/WebKit/public:blink_headers",
     "//third_party/icu",
     "//third_party/leveldatabase",
     "//ui/chromeos/resources",
   ]
   data = [
     "//chromeos/test/data/",
   ]
 }
 
 proto_library("device_policy_proto") {
   sources = [
     "policy/proto/chrome_device_policy.proto",
     "policy/proto/install_attributes.proto",
   ]
 }
 
 proto_library("attestation_proto") {
   sources = [
     "attestation/attestation_key_payload.proto",
   ]
 }