[Sync] Move snapshot cache from SBHI to PSS.

components/sync/engine/sync_engine_host.h

 // 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.
 
 #ifndef COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_HOST_H_
 #define COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_HOST_H_
 
 #include <string>
 
 #include "components/sync/base/model_type.h"
@@ skipping 30 matching lines @@
   // |js_backend| is what about:sync interacts with. It is initialized only if
   // |success| is true.
   virtual void OnEngineInitialized(
       ModelTypeSet initial_types,
       const WeakHandle<JsBackend>& js_backend,
       const WeakHandle<DataTypeDebugInfoListener>& debug_info_listener,
       const std::string& cache_guid,
       bool success) = 0;
 
   // The engine queried the server recently and received some updates.
-  virtual void OnSyncCycleCompleted() = 0;
+  virtual void OnSyncCycleCompleted(const SyncCycleSnapshot& snapshot) = 0;
 
   // Informs the host of some network event. These notifications are disabled by
   // default and must be enabled through an explicit request to the SyncEngine.
   //
   // It's disabled by default to avoid copying data across threads when no one
   // is listening for it.
   virtual void OnProtocolEvent(const ProtocolEvent& event) = 0;
 
   // Called when we receive an updated commit counter for a directory type.
   //
@@ skipping 70 matching lines @@
   // |nigori_state| contains the new (post custom passphrase) encryption keys
   // and can be used to restore SyncEncryptionHandler's state across sync
   // engine instances. See also SyncEncryptionHandlerImpl::RestoreNigori.
   virtual void OnLocalSetPassphraseEncryption(
       const SyncEncryptionHandler::NigoriState& nigori_state) = 0;
 };
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_ENGINE_SYNC_ENGINE_HOST_H_