Oilpan: cleanup based on review comments after removal of TreeShared.

Source/wtf/PassRefPtr.h

Index: Source/wtf/PassRefPtr.h
diff --git a/Source/wtf/PassRefPtr.h b/Source/wtf/PassRefPtr.h
index 1d21a538bf53329ca589d9de5783c4c86d614c51..821de5b29a221e6889f004180bb260f423a1a5b7 100644
--- a/Source/wtf/PassRefPtr.h
+++ b/Source/wtf/PassRefPtr.h
@@ -138,6 +138,16 @@ namespace WTF {
         return a == b.get();
     }
 
+    template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const U& b)
+    {
+        return a.get() == &b;
+    }
+
+    template<typename T, typename U> inline bool operator==(const T& a, const PassRefPtr<U>& b)
+    {
+        return &a == b.get();
+    }
+
     template<typename T, typename U> inline bool operator==(const PassRefPtr<T>& a, const RawPtr<U>& b)
     {
         return a.get() == b.get();
@@ -173,6 +183,16 @@ namespace WTF {
         return a != b.get();
     }
 
+    template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const U& b)
+    {
+        return a.get() != &b;
+    }
+
+    template<typename T, typename U> inline bool operator!=(const T& a, const PassRefPtr<U>& b)
+    {
+        return &a != b.get();
+    }
+
     template<typename T, typename U> inline bool operator!=(const PassRefPtr<T>& a, const RawPtr<U>& b)
     {
         return a.get() != b.get();