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

sync/test/fake_server/fake_server_verifier.cc

 // 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.
 
 #include "sync/test/fake_server/fake_server_verifier.h"
 
 #include "base/json/json_writer.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/values.h"
 #include "sync/internal_api/public/base/model_type.h"
@@ skipping 35 matching lines @@
 
   return AssertionFailure() << "Sessions hierarchies are not equal. "
                             << "FakeServer contents: " << actual.ToString()
                             << "; Expected contents: " << expected.ToString();
 }
 
 // Caller maintains ownership of |entities|.
 string ConvertFakeServerContentsToString(
     const base::DictionaryValue& entities) {
   string entities_str;
-  if (!JSONWriter::WriteWithOptions(&entities,
-                                    JSONWriter::OPTIONS_PRETTY_PRINT,
+  if (!JSONWriter::WriteWithOptions(entities, JSONWriter::OPTIONS_PRETTY_PRINT,
                                     &entities_str)) {
     entities_str = "Could not convert FakeServer contents to string.";
   }
   return "FakeServer contents:\n" + entities_str;
 }
 
 }  // namespace
 
 FakeServerVerifier::FakeServerVerifier(FakeServer* fake_server)
     : fake_server_(fake_server) { }
@@ skipping 109 matching lines @@
         return AssertionFailure() << "Malformed data: Tab entity not found.";
       }
       tab_urls.insert(tab_ids_to_urls[tab_id]);
     }
     actual_sessions.AddWindow(tab_urls);
   }
   return VerifySessionsHierarchyEquality(expected_sessions, actual_sessions);
 }
 
 }  // namespace fake_server