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

chrome/installer/util/installation_validator_unittest.cc

Index: chrome/installer/util/installation_validator_unittest.cc
diff --git a/chrome/installer/util/installation_validator_unittest.cc b/chrome/installer/util/installation_validator_unittest.cc
index c181aa05a526722c025874fbdea782ad265c90c8..a6571e9dd2ff1532ceab75184b2b3d1a04b62b02 100644
--- a/chrome/installer/util/installation_validator_unittest.cc
+++ b/chrome/installer/util/installation_validator_unittest.cc
@@ -282,16 +282,11 @@ class InstallationValidatorTest
       FakeInstallationState* state);
   void TearDown() override;
 
-  static logging::LogMessageHandlerFunction old_log_message_handler_;
   static ValidationErrorRecipient* validation_error_recipient_;
   static InstallationTypeToModifiers* type_to_modifiers_;
 };
 
 // static
-logging::LogMessageHandlerFunction
-    InstallationValidatorTest::old_log_message_handler_ = NULL;
-
-// static
 InstallationValidatorTest::ValidationErrorRecipient*
     InstallationValidatorTest::validation_error_recipient_ = NULL;
 
@@ -311,8 +306,7 @@ int InstallationValidatorTest::GetChannelModifiers(
 // static
 void InstallationValidatorTest::SetUpTestCase() {
   DCHECK(type_to_modifiers_ == NULL);
-  old_log_message_handler_ = logging::GetLogMessageHandler();
-  logging::SetLogMessageHandler(&HandleLogMessage);
+  logging::PushLogMessageHandler(&HandleLogMessage);
 
   type_to_modifiers_ = new InstallationTypeToModifiers();
   InstallationTypeToModifiers& ttm = *type_to_modifiers_;
@@ -330,8 +324,7 @@ void InstallationValidatorTest::SetUpTestCase() {
 
 // static
 void InstallationValidatorTest::TearDownTestCase() {
-  logging::SetLogMessageHandler(old_log_message_handler_);
-  old_log_message_handler_ = NULL;
+  logging::PopLogMessageHandler();
 
   delete type_to_modifiers_;
   type_to_modifiers_ = NULL;
@@ -360,9 +353,6 @@ bool InstallationValidatorTest::HandleLogMessage(int severity,
     return true;
   }
 
-  if (old_log_message_handler_ != NULL)
-    return (old_log_message_handler_)(severity, file, line, message_start, str);
-
   return false;
 }