[Sync] Convert SyncSessionSnapshot to a copy-able class.

chrome/browser/sync/profile_sync_service.h

 // 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.
 
 #ifndef CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 #define CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_
 #pragma once
 
 #include <list>
 #include <string>
@@ skipping 30 matching lines @@
 class ProfileSyncComponentsFactory;
 class SigninManager;
 class SyncGlobalError;
 
 namespace browser_sync {
 class BackendMigrator;
 class ChangeProcessor;
 class DataTypeManager;
 class JsController;
 class SessionModelAssociator;
-namespace sessions { struct SyncSessionSnapshot; }
+namespace sessions { class SyncSessionSnapshot; }
 }
 
 namespace sync_api {
 class BaseTransaction;
 struct SyncCredentials;
 struct UserShare;
 }
 
 namespace sync_pb {
 class EncryptedData;
@@ skipping 291 matching lines @@
   // TODO(akalin): This is called mostly by ModelAssociators and
   // tests.  Figure out how to pass the handle to the ModelAssociators
   // directly, figure out how to expose this to tests, and remove this
   // function.
   virtual sync_api::UserShare* GetUserShare() const;
 
   // TODO(akalin): These two functions are used only by
   // ProfileSyncServiceHarness.  Figure out a different way to expose
   // this info to that class, and remove these functions.
 
-  virtual const browser_sync::sessions::SyncSessionSnapshot*
+  virtual browser_sync::sessions::SyncSessionSnapshot
       GetLastSessionSnapshot() const;
 
   // Returns whether or not the underlying sync engine has made any
   // local changes to items that have not yet been synced with the
   // server.
   bool HasUnsyncedItems() const;
 
   // Used by ProfileSyncServiceHarness.  May return NULL.
   browser_sync::BackendMigrator* GetBackendMigratorForTest();
 
@@ skipping 372 matching lines @@
   bool setup_in_progress_;
 
   DISALLOW_COPY_AND_ASSIGN(ProfileSyncService);
 };
 
 bool ShouldShowActionOnUI(
     const browser_sync::SyncProtocolError& error);
 
 
 #endif  // CHROME_BROWSER_SYNC_PROFILE_SYNC_SERVICE_H_