Index: modules/javafx.web/src/main/native/Source/WTF/wtf/MemoryPressureHandler.h
--- modules/javafx.web/src/main/native/Source/WTF/wtf/MemoryPressureHandler.h.orig
+++ modules/javafx.web/src/main/native/Source/WTF/wtf/MemoryPressureHandler.h
@@ -97,7 +97,7 @@ class MemoryPressureHandler { (public)
     WTF_EXPORT_PRIVATE void setMemoryFootprintPollIntervalForTesting(Seconds);
     WTF_EXPORT_PRIVATE void setShouldUsePeriodicMemoryMonitor(bool);
 
-#if OS(LINUX) || OS(FREEBSD) || OS(HAIKU) || OS(QNX)
+#if OS(LINUX) || OS(FREEBSD) || OS(HAIKU) || OS(QNX) || OS(OPENBSD)
     WTF_EXPORT_PRIVATE void triggerMemoryPressureEvent(bool isCritical);
 #endif
 
@@ -268,7 +268,7 @@ class MemoryPressureHandler { (public)
     Win32Handle m_lowMemoryHandle;
 #endif
 
-#if OS(LINUX) || OS(FREEBSD) || OS(HAIKU) || OS(QNX)
+#if OS(LINUX) || OS(FREEBSD) || OS(HAIKU) || OS(QNX) || OS(OPENBSD)
     RunLoop::Timer m_holdOffTimer;
     void holdOffTimerFired();
 #endif
