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

sync/internal_api/syncapi_unittest.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.
 
 // Unit tests for the SyncApi. Note that a lot of the underlying
 // functionality is provided by the Syncable layer, which has its own
 // unit tests. We'll test SyncApi specific things in this harness.
 
 #include <cstddef>
 #include <map>
@@ skipping 658 matching lines @@
     return new TestHttpPostProviderInterface();
   }
   virtual void Destroy(HttpPostProviderInterface* http) OVERRIDE {
     delete http;
   }
 };
 
 class SyncManagerObserverMock : public SyncManager::Observer {
  public:
   MOCK_METHOD1(OnSyncCycleCompleted,
-               void(const SyncSessionSnapshot*));  // NOLINT
+               void(const SyncSessionSnapshot&));  // NOLINT
   MOCK_METHOD2(OnInitializationComplete,
                void(const WeakHandle<JsBackend>&, bool));  // NOLINT
   MOCK_METHOD1(OnConnectionStatusChange, void(ConnectionStatus));  // NOLINT
   MOCK_METHOD2(OnPassphraseRequired,
                void(sync_api::PassphraseRequiredReason,
                     const sync_pb::EncryptedData&));  // NOLINT
   MOCK_METHOD0(OnPassphraseAccepted, void());  // NOLINT
   MOCK_METHOD1(OnBootstrapTokenUpdated, void(const std::string&));  // NOLINT
   MOCK_METHOD0(OnStopSyncingPermanently, void());  // NOLINT
   MOCK_METHOD1(OnUpdatedToken, void(const std::string&));  // NOLINT
@@ skipping 1820 matching lines @@
     EXPECT_EQ(title, node.GetTitle());
     EXPECT_EQ(GURL(url2), node.GetURL());
     const syncable::Entry* node_entry = node.GetEntry();
     EXPECT_EQ(kEncryptedString, node_entry->Get(NON_UNIQUE_NAME));
     const sync_pb::EntitySpecifics& specifics = node_entry->Get(SPECIFICS);
     EXPECT_TRUE(specifics.has_encrypted());
   }
 }
 
 }  // namespace browser_sync