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

third_party/libphonenumber/cpp/src/logger_adapter.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_LOGGER_ADAPTER_H_
+#define I18N_PHONENUMBERS_LOGGER_ADAPTER_H_
+
+#include <string>
+
+using std::string;
+
+namespace i18n {
+namespace phonenumbers {
+
+// Implement this 'interface' to override the way logging is handled
+// in the library.
+class LoggerAdapter {
+ public:
+  virtual ~LoggerAdapter();
+
+  // Logging methods
+  virtual void Fatal(const string& msg) const = 0;
+
+  virtual void Error(const string& msg) const = 0;
+
+  virtual void Warning(const string& msg) const = 0;
+
+  virtual void Info(const string& msg) const = 0;
+
+  virtual void Debug(const string& msg) const = 0;
+};
+
+}  // namespace phonenumbers
+}  // namespace i18n
+
+#endif  // I18N_PHONENUMBERS_LOGGER_ADAPTER_H_