components: Remove 'ui' dependencies from json_schema and user_prefs targets.

components/json_schema.gypi

 # Copyright 2013 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.
 
 {
   'targets': [
     {
       'target_name': 'json_schema',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
-        '../ui/gfx/gfx.gyp:gfx',
-        '../ui/ui.gyp:ui',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'json_schema/json_schema_constants.cc',
         'json_schema/json_schema_constants.h',
         'json_schema/json_schema_validator.cc',
         'json_schema/json_schema_validator.h',
       ],
     },
   ],
 }