Allow multiple logging::LogMessage{Handler,Listener}s

remoting/client/plugin/chromoting_instance.cc

Index: remoting/client/plugin/chromoting_instance.cc
diff --git a/remoting/client/plugin/chromoting_instance.cc b/remoting/client/plugin/chromoting_instance.cc
index 2c2ab84493cca4345e29b47d54b10d7a46870153..757783802d9d6fb02e98b2677f0a4c5e22c96196 100644
--- a/remoting/client/plugin/chromoting_instance.cc
+++ b/remoting/client/plugin/chromoting_instance.cc
@@ -170,8 +170,8 @@ ChromotingInstance::ChromotingInstance(PP_Instance pp_instance)
   thread_wrapper_ =
       jingle_glue::JingleThreadWrapper::WrapTaskRunner(plugin_task_runner_);
 
-  // Register a global log handler.
-  ChromotingInstance::RegisterLogMessageHandler();
+  // Register a log listener.
+  log_to_ui_ = base::MakeUnique<LogToUI>();
 
   nacl_io_init_ppapi(pp_instance, pp::Module::Get()->get_browser_interface());
   mount("", "/etc", "memfs", 0, "");
@@ -1036,15 +1036,6 @@ void ChromotingInstance::UpdatePerfStatsInUI() {
   PostLegacyJsonMessage("onPerfStats", std::move(data));
 }
 
-// static
-void ChromotingInstance::RegisterLogMessageHandler() {
-  base::AutoLock lock(g_logging_lock.Get());
-
-  // Set up log message handler.
-  // This is not thread-safe so we need it within our lock.
-  logging::SetLogMessageHandler(&LogToUI);
-}
-
 void ChromotingInstance::RegisterLoggingInstance() {
   base::AutoLock lock(g_logging_lock.Get());
   g_logging_instance = pp_instance();
@@ -1061,10 +1052,20 @@ void ChromotingInstance::UnregisterLoggingInstance() {
   g_logging_instance = 0;
 }
 
-// static
-bool ChromotingInstance::LogToUI(int severity, const char* file, int line,
-                                 size_t message_start,
-                                 const std::string& str) {
+class LogToUI : logging::LogMessageListener {
+ public:
+  void OnMessage(int severity,
+                 const char* file,
+                 int line,
+                 size_t message_start,
+                 const std::string& str) override;
+};
+
+void LogToUI::OnMessage(int severity,
+                        const char* file,
+                        int line,
+                        size_t message_start,
+                        const std::string& str) {
   PP_LogLevel log_level = PP_LOGLEVEL_ERROR;
   switch (severity) {
     case logging::LOG_INFO:
@@ -1097,8 +1098,6 @@ bool ChromotingInstance::LogToUI(int severity, const char* file, int line,
   // may crash before the message is delivered to the console.
   if (severity == logging::LOG_FATAL)
     base::PlatformThread::Sleep(base::TimeDelta::FromSeconds(1));
-
-  return false;
 }
 
 bool ChromotingInstance::IsConnected() {