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

base/logging_win.h

Index: base/logging_win.h
diff --git a/base/logging_win.h b/base/logging_win.h
index cdde7bb687cbbd524a0b5e412e0a2c6714b06f3f..fa47b578a3b9119c5d407e4cef9d00e1a8b85ca9 100644
--- a/base/logging_win.h
+++ b/base/logging_win.h
@@ -51,15 +51,17 @@ enum LogMessageTypes {
   LOG_MESSAGE_FULL = 12,
 };
 
+class WinLogMessageHandler : LogMessageHandler {

[grt (UTC plus 2), 2016/07/27 20:38:21]

move this into the private: section of LogEventProvider so you don't need the
"friend"?

[wychen, 2016/08/01 16:12:26]

Done.

+  bool OnMessage(logging::LogSeverity severity, const char* file,

[grt (UTC plus 2), 2016/07/27 20:38:21]

public:

[wychen, 2016/08/01 16:12:26]

Done.

+      int line, size_t message_start, const std::string& str) override;
+};
+
 // Trace provider class to drive log control and transport
 // with Event Tracing for Windows.
 class BASE_EXPORT LogEventProvider : public base::win::EtwTraceProvider {
  public:
   static LogEventProvider* GetInstance();
 
-  static bool LogMessage(logging::LogSeverity severity, const char* file,
-      int line, size_t message_start, const std::string& str);
-
   static void Initialize(const GUID& provider_name);
   static void Uninitialize();
 
@@ -69,6 +71,7 @@ class BASE_EXPORT LogEventProvider : public base::win::EtwTraceProvider {
   void OnEventsDisabled() override;
 
  private:
+  friend class WinLogMessageHandler;
   LogEventProvider();
 
   // The log severity prior to OnEventsEnabled,