Remove CachingValueStore in favor of an async ValueStoreFrontend.

chrome/chrome_browser.gypi

 # Copyright (c) 2012 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': 'browser',
       'type': 'static_library',
@@ skipping 4024 matching lines @@
         'browser/usb/usb_device.cc',
         'browser/usb/usb_device.h',
         'browser/usb/usb_service.cc',
         'browser/usb/usb_service.h',
         'browser/usb/usb_service_factory.cc',
         'browser/usb/usb_service_factory.h',
         'browser/user_style_sheet_watcher.cc',
         'browser/user_style_sheet_watcher.h',
         'browser/user_style_sheet_watcher_factory.cc',
         'browser/user_style_sheet_watcher_factory.h',
-        'browser/value_store/caching_value_store.cc',
-        'browser/value_store/caching_value_store.h',
         'browser/value_store/failing_value_store.cc',
         'browser/value_store/failing_value_store.h',
         'browser/value_store/leveldb_value_store.cc',
         'browser/value_store/leveldb_value_store.h',
         'browser/value_store/testing_value_store.cc',
         'browser/value_store/testing_value_store.h',
         'browser/value_store/value_store_change.cc',
         'browser/value_store/value_store_change.h',
+        'browser/value_store/value_store_frontend.cc',
+        'browser/value_store/value_store_frontend.h',
         'browser/value_store/value_store.cc',
         'browser/value_store/value_store.h',
         'browser/view_type_utils.cc',
         'browser/view_type_utils.h',
         'browser/visitedlink/visitedlink_event_listener.cc',
         'browser/visitedlink/visitedlink_event_listener.h',
         'browser/visitedlink/visitedlink_master.cc',
         'browser/visitedlink/visitedlink_master.h',
         'browser/web_applications/web_app.cc',
         'browser/web_applications/web_app.h',
@@ skipping 1122 matching lines @@
         'browser/metrics/proto/study.proto',
       ],
       'variables': {
         'proto_in_dir': 'browser/metrics/proto',
         'proto_out_dir': 'chrome/browser/metrics/proto',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }