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

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..2f230affb83990586b9365f016005cbdb6769de9 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::PushLogMessageHandler(LogMessageHandler);
 }
 
 void MockLog::StopCapturingLogs() {
@@ -45,7 +44,7 @@ void MockLog::StopCapturingLogs() {
   RAW_CHECK(g_instance_ == this);
 
   is_capturing_logs_ = false;
-  logging::SetLogMessageHandler(previous_handler_);
+  logging::PopLogMessageHandler();
   g_instance_ = nullptr;
 }