Supplement should have a Member to the corresponding Supplementable object (Part 1)

third_party/WebKit/Source/core/dom/CSSSelectorWatch.h

Index: third_party/WebKit/Source/core/dom/CSSSelectorWatch.h
diff --git a/third_party/WebKit/Source/core/dom/CSSSelectorWatch.h b/third_party/WebKit/Source/core/dom/CSSSelectorWatch.h
index 00e7b22bea86261780d296a5dbc95ad63c8ffac4..f36a0e5f5eac1a1b5f8221674f343e90d7cb2756 100644
--- a/third_party/WebKit/Source/core/dom/CSSSelectorWatch.h
+++ b/third_party/WebKit/Source/core/dom/CSSSelectorWatch.h
@@ -60,9 +60,7 @@ public:
 private:
     explicit CSSSelectorWatch(Document&);
     void callbackSelectorChangeTimerFired(Timer<CSSSelectorWatch>*);
-    Document& document() const { return *m_document; }
-
-    Member<Document> m_document;
+    Document& document() const { return *host(); }

[sof, 2016/07/13 07:46:08]

assert/check for non-nullness?

[haraken, 2016/07/13 07:51:25]

Hmm, maybe CSSSelectorWatch does want to keep a strong reference to Document?
Then we should keep Member<Document>.

What we can remove is a weak reference to the host object (e.g., XXXObservers).

[sof, 2016/07/13 07:54:07]

How about going with "Member<T> m_host" ?

 
     HeapVector<Member<StyleRule>> m_watchedCallbackSelectors;