Qualify RuntimeEnabledFeatures.h and remove unnecessary include dir.

Source/core/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")
 import("//third_party/WebKit/Source/bindings/bindings.gni")
 import("//third_party/WebKit/Source/bindings/core/v8/generated.gni")
 import("//third_party/WebKit/Source/bindings/modules/modules.gni")
 import("//third_party/WebKit/Source/bindings/modules/v8/generated.gni")
 import("//third_party/WebKit/Source/bindings/scripts/scripts.gni")
@@ skipping 25 matching lines @@
 core_config_add += [ "//build/config/compiler:wexit_time_destructors" ]
 
 config("core_include_dirs") {
   include_dirs = [
     "..",
     "../..",
     # FIXME: Remove these once core scripts generates qualified
     # includes correctly: http://crbug.com/358074
     blink_core_output_dir,
     blink_modules_output_dir,
-    blink_platform_output_dir,
     bindings_core_v8_output_dir,
     bindings_modules_v8_output_dir,
     # FIXME: MediaQueryListListener.cpp includes
     # "gen/blink/bindings/core/v8/V8MediaQueryList.h" relative to "gen/blink"
     # which is busted. This file (and any other ones that do a similar thing)
     # should be fixed and this can be removed.
     "$root_gen_dir/blink",
   ]
   if (is_android && use_openmax_dl_fft) {
     include_dirs += [ "//third_party/openmax_dl" ]
@@ skipping 1006 matching lines @@
     "$blink_core_output_dir/{{source_name_part}}.h",
   ]
   args = [
     "{{source}}",
     rel_blink_core_gen_dir,
     bison_exe,
   ]
 
   deps = make_core_generated_deps
 }