Fix IsPrecachingAllowed() to check Sync instead of Data Saver.

components/precache.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': [
     {
       # GN Version: //components/precache/content
       'target_name': 'precache_content',
       'type': 'static_library',
       'dependencies': [
         'precache_core',
         '../base/base.gyp:base',
         '../content/content.gyp:content_browser',
         '../url/url.gyp:url_lib',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         # Note: sources list duplicated in GN build.
         'precache/content/precache_manager.cc',
         'precache/content/precache_manager.h',
-        'precache/content/precache_manager_factory.cc',
-        'precache/content/precache_manager_factory.h',
       ],
     },
     {
       # GN version: //components/precache/core
       'target_name': 'precache_core',
       'type': 'static_library',
       'dependencies': [
         'precache_core_proto',
         '../base/base.gyp:base',
         '../third_party/protobuf/protobuf.gyp:protobuf_lite',
@@ skipping 54 matching lines @@
           '../base/base.gyp:base_java_test_support',
         ],
         'variables': {
           'java_in_dir': 'precache/android/javatests',
         },
         'includes': [ '../build/java.gypi' ],
       }],
     }],
   ],
 }