Convert JsonWriter::Write to taking a const ref for the in-param

sync/internal_api/public/sessions/sync_session_snapshot.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 "sync/internal_api/public/sessions/sync_session_snapshot.h"
 
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "sync/protocol/proto_enum_conversions.h"
@@ skipping 85 matching lines @@
     const std::string model_type = ModelTypeToString(static_cast<ModelType>(i));
     counter_entries->Set(model_type, type_entries.release());
   }
   value->Set("counter_entries", counter_entries.Pass());
   return value;
 }
 
 std::string SyncSessionSnapshot::ToString() const {
   std::string json;
   base::JSONWriter::WriteWithOptions(
-      ToValue().get(), base::JSONWriter::OPTIONS_PRETTY_PRINT, &json);
+      *ToValue(), base::JSONWriter::OPTIONS_PRETTY_PRINT, &json);
   return json;
 }
 
 const ProgressMarkerMap&
     SyncSessionSnapshot::download_progress_markers() const {
   return download_progress_markers_;
 }
 
 bool SyncSessionSnapshot::is_silenced() const {
   return is_silenced_;
@@ skipping 36 matching lines @@
   return num_to_delete_entries_by_type_;
 }
 
 sync_pb::GetUpdatesCallerInfo::GetUpdatesSource
 SyncSessionSnapshot::legacy_updates_source() const {
   return legacy_updates_source_;
 }
 
 }  // namespace sessions
 }  // namespace syncer