Oilpan: move DOMImplementation to the heap.

Source/core/dom/DOMImplementation.h

Index: Source/core/dom/DOMImplementation.h
diff --git a/Source/core/dom/DOMImplementation.h b/Source/core/dom/DOMImplementation.h
index f954c8fd6b9bd489843f83d1a1267b22bec7310a..a4765d2bc6f5ad744e2c39e2667618e667d7d7e8 100644
--- a/Source/core/dom/DOMImplementation.h
+++ b/Source/core/dom/DOMImplementation.h
@@ -40,14 +40,19 @@ class HTMLDocument;
 class KURL;
 class XMLDocument;
 
-class DOMImplementation : public ScriptWrappable {
-    WTF_MAKE_FAST_ALLOCATED;
+class DOMImplementation FINAL : public NoBaseWillBeGarbageCollectedFinalized<DOMImplementation>, public ScriptWrappable {
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
-    static PassOwnPtr<DOMImplementation> create(Document& document) { return adoptPtr(new DOMImplementation(document)); }
+    static PassOwnPtrWillBeRawPtr<DOMImplementation> create(Document* document)

[tkent, 2014/05/07 23:43:20]

Why do you change the argument type from a reference to a pointer?

[sof, 2014/05/08 05:24:13]

At the single call site, converting a pointer into a reference, only to convert
it back into a pointer (Member) is making work for questionable gain. Are there
some to be had?

[tkent, 2014/05/08 06:09:16]

Even in such case, the reference still has benefit as ever. It tells us that the
variable can't be null without any words.

[sof, 2014/05/08 06:14:53]

I'll switch back, but the lack of reviewing consistency is sub-optimal. i.e.,
asked in other ongoing dom/ reviews to switch away from refs in create()
signatures.

+    {
+        return adoptPtrWillBeNoop(new DOMImplementation(document));
+    }
 
-    void ref() { m_document.ref(); }
-    void deref() { m_document.deref(); }
-    Document& document() const { return m_document; }
+#if !ENABLE(OILPAN)
+    void ref() { m_document->ref(); }
+    void deref() { m_document->deref(); }
+#endif
+    Document& document() const { return *m_document.get(); }
 
     // DOM methods & attributes for DOMImplementation
     static bool hasFeature(const String& feature, const String& version);
@@ -66,10 +71,12 @@ public:
     static bool isTextMIMEType(const String&);
     static bool isJSONMIMEType(const String&);
 
+    void trace(Visitor*);
+
 private:
-    explicit DOMImplementation(Document&);
+    explicit DOMImplementation(Document*);
 
-    Document& m_document;
+    RawPtrWillBeMember<Document> m_document;
 };
 
 } // namespace WebCore