Move CSSCalcExpressionNode and subclasses to the oilpan heap.

Source/wtf/RawPtr.h

Index: Source/wtf/RawPtr.h
diff --git a/Source/wtf/RawPtr.h b/Source/wtf/RawPtr.h
index 8c111eafeaad4086755b00e3211ba56de2f67afa..92ed528412176cf40e8611d91501c36c7b7bbaab 100644
--- a/Source/wtf/RawPtr.h
+++ b/Source/wtf/RawPtr.h
@@ -45,9 +45,12 @@ class RawPtr {
 public:
     RawPtr() : m_ptr(0) { }
     RawPtr(T* ptr) : m_ptr(ptr) { }
-
+    RawPtr(const RawPtr& other)
+        : m_ptr(other.get())
+    {
+    }
     template<typename U>
-    explicit RawPtr(const RawPtr<U>& other)
+    RawPtr(const RawPtr<U>& other)
         : m_ptr(other.get())
     {
     }
@@ -68,12 +71,20 @@ public:
         return ptr;
     }
 
-    RawPtr& operator=(T* ptr)
+    template<typename U>
+    RawPtr& operator=(U* ptr)
     {
         m_ptr = ptr;
         return *this;
     }
 
+    template<typename U>
+    RawPtr& operator=(RawPtr<U> ptr)
+    {
+        m_ptr = ptr.get();
+        return *this;
+    }
+
     operator T*() const { return m_ptr; }
     T& operator*() const { return *m_ptr; }
     T* operator->() const { return m_ptr; }