Make Blink internal parts private dependencies.

content/child/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/child/child.gni")
 
 source_set("child") {
   # Targets external to content should always link to the public API.
@@ skipping 49 matching lines @@
     "//third_party/WebKit/public:image_resources",
     "//third_party/WebKit/public:resources",
     "//third_party/icu",
     "//ui/base",
     "//ui/events/gestures/blink",
     "//ui/gfx",
     "//ui/gfx/geometry",
     "//ui/gl",
     "//ui/native_theme",
     "//url",
+    "//v8",
   ]
 
   if (!use_default_render_theme) {
     sources -= [
       "webthemeengine_impl_default.cc",
       "webthemeengine_impl_default.h",
     ]
   }
 
   if (is_android) {
@@ skipping 20 matching lines @@
 
 # See comment at the top of //content/BUILD.gn for how this works.
 group("for_content_tests") {
   visibility = [ "//content/test/*" ]
   if (!is_component_build) {
     public_deps = [
       ":child",
     ]
   }
 }