Enable HitTestCache by default.

Source/core/layout/HitTestResult.cpp

Index: Source/core/layout/HitTestResult.cpp
diff --git a/Source/core/layout/HitTestResult.cpp b/Source/core/layout/HitTestResult.cpp
index 66a52ebe3536d0d2e92001b81ff40fff3ee16fd6..09d078958707690cfcc7df7186ef71d2e8206a1c 100644
--- a/Source/core/layout/HitTestResult.cpp
+++ b/Source/core/layout/HitTestResult.cpp
@@ -111,18 +111,6 @@ HitTestResult& HitTestResult::operator=(const HitTestResult& other)
     return *this;
 }
 
-unsigned HitTestResult::equalityScore(const HitTestResult& other) const
-{
-    return (m_hitTestRequest.equalForCacheability(other.m_hitTestRequest) << 7)
-        | ((m_innerNode == other.innerNode()) << 6)
-        | ((m_innerPossiblyPseudoNode == other.innerPossiblyPseudoNode()) << 5)
-        | ((m_pointInInnerNodeFrame == other.m_pointInInnerNodeFrame) << 4)
-        | ((m_localPoint == other.localPoint()) << 3)
-        | ((m_innerURLElement == other.URLElement()) << 2)
-        | ((m_scrollbar == other.scrollbar()) << 1)
-        | (m_isOverWidget == other.isOverWidget());
-}
-
 bool HitTestResult::equalForCacheability(const HitTestResult& other) const
 {
     return m_hitTestRequest.equalForCacheability(other.m_hitTestRequest)