Re-committing http://codereview.chromium.org/6803005/ after fixing multi-dll build:

third_party/libphonenumber/cpp/src/default_logger.h

+// Copyright (C) 2011 Google Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// Author: Philippe Liard
+
+#ifndef I18N_PHONENUMBERS_DEFAULT_LOGGER_H_
+#define I18N_PHONENUMBERS_DEFAULT_LOGGER_H_
+
+#include "logger_adapter.h"
+
+namespace i18n {
+namespace phonenumbers {
+
+enum LogLevel {
+  LOG_FATAL,
+  LOG_ERROR,
+  LOG_WARNING,
+  LOG_INFO,
+  LOG_DEBUG,
+};
+
+class DefaultLogger : public LoggerAdapter {
+ public:
+  virtual ~DefaultLogger();
+
+  DefaultLogger(LogLevel level = LOG_WARNING);
+
+  virtual void Fatal(const string& msg) const;
+
+  virtual void Error(const string& msg) const;
+
+  virtual void Warning(const string& msg) const;
+
+  virtual void Info(const string& msg) const;
+
+  virtual void Debug(const string& msg) const;
+
+ private:
+  LogLevel level_;
+};
+
+}  // namespace phonenumbers
+}  // namespace i18n
+
+# endif   // I18N_PHONENUMBERS_DEFAULT_LOGGER_H_