Reduce repetitive EventTarget subclassing

Source/core/page/Performance.cpp

Index: Source/core/page/Performance.cpp
diff --git a/Source/core/page/Performance.cpp b/Source/core/page/Performance.cpp
index 8d233d7d5e3037b0439d2a8069a98add41b74978..717c94ffb4b0aac6b97f41d380e4c98b894a276c 100644
--- a/Source/core/page/Performance.cpp
+++ b/Source/core/page/Performance.cpp
@@ -248,16 +248,6 @@ bool Performance::isResourceTimingBufferFull()
     return m_resourceTimingBuffer.size() >= m_resourceTimingBufferSize;
 }
 
-EventTargetData* Performance::eventTargetData()
-{
-    return &m_eventTargetData;
-}
-
-EventTargetData* Performance::ensureEventTargetData()
-{
-    return &m_eventTargetData;
-}
-
 void Performance::mark(const String& markName, ExceptionState& es)
 {
     if (!m_userTiming)