support multiple log message handlers in base/logging.h

base/test/mock_log.cc

Index: base/test/mock_log.cc
diff --git a/base/test/mock_log.cc b/base/test/mock_log.cc
index a09000d8ed7f9e3080ff06a64cb060c76fa591f6..83cb246efa9184db4f853a73ccd6fcc47e7cb8c3 100644
--- a/base/test/mock_log.cc
+++ b/base/test/mock_log.cc
@@ -31,8 +31,7 @@ void MockLog::StartCapturingLogs() {
 
   is_capturing_logs_ = true;
   g_instance_ = this;
-  previous_handler_ = logging::GetLogMessageHandler();
-  logging::SetLogMessageHandler(LogMessageHandler);
+  logging::AddLogMessageHandler(LogMessageHandler);
 }
 
 void MockLog::StopCapturingLogs() {
@@ -45,15 +44,14 @@ void MockLog::StopCapturingLogs() {
   RAW_CHECK(g_instance_ == this);
 
   is_capturing_logs_ = false;
-  logging::SetLogMessageHandler(previous_handler_);
+  logging::RemoveLogMessageHandler(LogMessageHandler);
   g_instance_ = nullptr;
 }
 
 // static
 bool MockLog::LogMessageHandler(int severity,
-                                const char* file,
+                                const std::string& file,
                                 int line,
-                                size_t message_start,
                                 const std::string& str) {
   // gMock guarantees thread-safety for calling a mocked method
   // (https://github.com/google/googlemock/blob/master/googlemock/docs/CookBook.md#using-google-mock-and-threads)
@@ -61,7 +59,7 @@ bool MockLog::LogMessageHandler(int severity,
   // with LogMessageHandler.
   AutoLock scoped_lock(g_lock);
 
-  return g_instance_->Log(severity, file, line, message_start, str);
+  return g_instance_->Log(severity, file, line, str);
 }
 
 }  // namespace test