Add ExtensionsApiClient interface, use it in the storage API SettingsFrontend

chrome/browser/extensions/api/storage/settings_frontend.cc

 // 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.
 
 #include "chrome/browser/extensions/api/storage/settings_frontend.h"
 
 #include <limits>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/files/file_path.h"
 #include "base/json/json_reader.h"
 #include "base/lazy_instance.h"
 #include "chrome/browser/extensions/api/storage/leveldb_settings_storage_factory.h"
 #include "chrome/browser/extensions/api/storage/sync_or_local_value_store_cache.h"
-#include "chrome/browser/extensions/extension_service.h"
 #include "chrome/common/extensions/api/storage.h"
 #include "content/public/browser/browser_context.h"
 #include "content/public/browser/browser_thread.h"
+#include "extensions/browser/api/extensions_api_client.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_registry.h"
 #include "extensions/browser/extension_system.h"
 
-#if defined(ENABLE_CONFIGURATION_POLICY)
-#include "chrome/browser/extensions/api/storage/managed_value_store_cache.h"
-#endif
-
 using content::BrowserContext;
 using content::BrowserThread;
 
 namespace extensions {
 
 namespace storage = api::storage;
 
 namespace {
 
 base::LazyInstance<ProfileKeyedAPIFactory<SettingsFrontend> > g_factory =
@@ skipping 93 matching lines @@
           observers_,
           browser_context_path);
   caches_[settings_namespace::SYNC] =
       new SyncOrLocalValueStoreCache(
           settings_namespace::SYNC,
           factory,
           sync_quota_limit_,
           observers_,
           browser_context_path);
 
-#if defined(ENABLE_CONFIGURATION_POLICY)
-  caches_[settings_namespace::MANAGED] =
-      new ManagedValueStoreCache(
-          browser_context_,
-          factory,
-          observers_);
-#endif
+  // Add any additional caches the embedder supports (for example, a cache
+  // for chrome.storage.managed).
+  ExtensionsApiClient::Get()->AddAdditionalValueStoreCaches(
+      browser_context_, factory, observers_, &caches_);
 }
 
 SettingsFrontend::~SettingsFrontend() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   observers_->RemoveObserver(browser_context_observer_.get());
   for (CacheMap::iterator it = caches_.begin(); it != caches_.end(); ++it) {
     ValueStoreCache* cache = it->second;
     cache->ShutdownOnUI();
     BrowserThread::DeleteSoon(BrowserThread::FILE, FROM_HERE, cache);
   }
@@ skipping 67 matching lines @@
 SettingsFrontend::GetFactoryInstance() {
   return g_factory.Pointer();
 }
 
 // static
 const char* SettingsFrontend::service_name() {
   return "SettingsFrontend";
 }
 
 }  // namespace extensions