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

base/test/mock_log.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef BASE_TEST_MOCK_LOG_H_
 #define BASE_TEST_MOCK_LOG_H_
 
 #include <stddef.h>
 
 #include <string>
@@ skipping 42 matching lines @@
   ~MockLog();
 
   // Starts log capturing if the object isn't already doing so.
   // Otherwise crashes.
   void StartCapturingLogs();
 
   // Stops log capturing if the object is capturing logs.  Otherwise crashes.
   void StopCapturingLogs();
 
   // Log method is invoked for every log message before it's sent to other log
-  // destinations (if any).  The method should return true to signal that it
-  // handled the message and the message should not be sent to other log
-  // destinations.
+  // destinations (if any).
   MOCK_METHOD5(Log,
-               bool(int severity,
+               void(int severity,
                     const char* file,
                     int line,
                     size_t message_start,
                     const std::string& str));
 
  private:
   // The currently active mock log.
   static MockLog* g_instance_;
 
   // Lock protecting access to g_instance_.
   static Lock g_lock;
 
-  // Static function which is set as the logging message handler.
+  // Static function which is set as the logging message listener.
   // Called once for each message.
-  static bool LogMessageHandler(int severity,
-                                const char* file,
-                                int line,
-                                size_t message_start,
-                                const std::string& str);
+  static void LogMessageListener(int severity,
+                                 const char* file,
+                                 int line,
+                                 size_t message_start,
+                                 const std::string& str);
 
   // True if this object is currently capturing logs.
   bool is_capturing_logs_;
 
-  // The previous handler to restore when the MockLog is destroyed.
-  logging::LogMessageHandlerFunction previous_handler_;
-
   DISALLOW_COPY_AND_ASSIGN(MockLog);
 };
 
 }  // namespace test
 }  // namespace base
 
 #endif  // BASE_TEST_MOCK_LOG_H_