// Sets the Log Message Handler that gets passed every log message before
// it's sent to other log destinations (if any).
// Returns true to signal that it handled the message and the message
// should not be sent to other log destinations.
typedef bool (*LogMessageHandlerFunction)(int severity,
    const char* file, int line, size_t message_start, const std::string& str);
BASE_EXPORT void SetLogMessageHandler(LogMessageHandlerFunction handler);
BASE_EXPORT LogMessageHandlerFunction GetLogMessageHandler();