Oilpan: Replace RefPtrs to Node and its subclasses in core/dom/ with Oilpan transtion types.

Source/wtf/Assertions.h

Index: Source/wtf/Assertions.h
diff --git a/Source/wtf/Assertions.h b/Source/wtf/Assertions.h
index ca91dd2bcf039897f93153a6b7e186ac617cf999..b82208141de1c3c121a87135bfca7ba0ecb9b125 100644
--- a/Source/wtf/Assertions.h
+++ b/Source/wtf/Assertions.h
@@ -380,6 +380,12 @@ static inline void UNREACHABLE_FOR_PLATFORM()
     inline bool operator!=(const PassRefPtr<thisType>& a, const thisType& b) { return !(a == b); } \
     inline bool operator!=(const thisType& a, const PassRefPtr<thisType>& b) { return !(a == b); }
 
+#define DEFINE_COMPARISON_OPERATORS_WITH_REFERENCES_RAWPTR(thisType) \
+    inline bool operator==(const RawPtr<thisType>& a, const thisType& b) { return a.get() == &b; } \

[Mads Ager (chromium), 2014/06/04 09:27:26]

This is in line with what is being done now, so just ignore this comment. ;-)

I can't resist: I think this is a bad idea. We should not implicitly be taking
the address of something for comparison with a RawPtr. When we use references
and want to compare with a pointer we should do that and explicitly use the '&'
to make that clear. Using references and then hiding the places where what you
really want is a pointer seems like a bad idea that is currently spreading in
the source base.

[Erik Corry, 2014/06/04 09:35:47]

I agree that the need for this indicates we are using references as pointers,
instead of just using pointers as pointers, which would be more natural. That
causes a lot of clumsy code, so we 'fix' the issue one type at a time (in this
case for Node*/Node&) with some rather confusing operators that will invisibly
do pointer comparisons on references.

But that's a general tendency in Blink which will not be changed in this CL, so
this LGTM from the point of view of committing this change.

[tkent, 2014/06/05 00:22:27]

As you know, it's off-topic.  I don't think we have project-wide consensus about
this, and I recommend to discuss this on blink-dev if you don't like this.

Anyway, I found this was necessary for just one instance,
ContainerNode::parserInsertBefore. So I removed this macro.

+    inline bool operator==(const thisType& a, const RawPtr<thisType>& b) { return &a == b.get(); } \
+    inline bool operator!=(const RawPtr<thisType>& a, const thisType& b) { return !(a == b); } \
+    inline bool operator!=(const thisType& a, const RawPtr<thisType>& b) { return !(a == b); }
+
 /* DEFINE_TYPE_CASTS */
 
 #define DEFINE_TYPE_CASTS(thisType, argumentType, argumentName, pointerPredicate, referencePredicate) \