enable -Wstring-conversion when compiling with clang

sync/syncable/entry_kernel.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/syncable/entry_kernel.h"
 
 #include "base/string_number_conversions.h"
 #include "sync/protocol/proto_value_conversions.h"
 #include "sync/syncable/syncable_enum_conversions.h"
 #include "sync/util/cryptographer.h"
@@ skipping 56 matching lines @@
     const std::string& key = GetProtoFieldString(field);
 
     base::DictionaryValue* value = NULL;
     sync_pb::EntitySpecifics decrypted;
     const sync_pb::EncryptedData& encrypted = kernel.ref(field).encrypted();
     if (cryptographer &&
         kernel.ref(field).has_encrypted() &&
         cryptographer->CanDecrypt(encrypted) &&
         cryptographer->Decrypt(encrypted, &decrypted)) {
       value = EntitySpecificsToValue(decrypted);
-      value->SetBoolean("encrypted", "true");
+      value->SetBoolean("encrypted", true);
     } else {
       value = EntitySpecificsToValue(kernel.ref(field));
     }
     dictionary_value->Set(key, value);
   }
 }
 
 // Helper functions for SetFieldValues().
 
 base::StringValue* Int64ToValue(int64 i) {
@@ skipping 98 matching lines @@
 base::DictionaryValue* EntryKernelMutationToValue(
     const EntryKernelMutation& mutation) {
   base::DictionaryValue* dict = new base::DictionaryValue();
   dict->Set("original", mutation.original.ToValue(NULL));
   dict->Set("mutated", mutation.mutated.ToValue(NULL));
   return dict;
 }
 
 }  // namespace syncer
 }  // namespace syncable