Bug 578696 part 5. Stop holding strong refs when calling CharacterDataWillChange. r=sicking

content/base/public/nsIMutationObserver.h

@@ -117,6 +117,12 @@ public:
    * @param aDocument The owner-document of aContent. Can be null.
    * @param aContent  The piece of content that changed. Is never null.
    * @param aInfo     The structure with information details about the change.
+   *
+   * @note Callers of this method might not hold a strong reference to the
+   *       observer.  The observer is responsible for making sure it stays
+   *       alive for the duration of the call as needed.  The observer may
+   *       assume that this call will happen when there are script blockers on
+   *       the stack.
    */
   virtual void CharacterDataWillChange(nsIDocument *aDocument,
                                        nsIContent* aContent,

content/base/src/nsNodeUtils.cpp

@@ -114,7 +114,7 @@ nsNodeUtils::CharacterDataWillChange(nsIContent* aContent,
                                      CharacterDataChangeInfo* aInfo)
 {
   nsIDocument* doc = aContent->GetOwnerDoc();
-  IMPL_STRONGREF_MUTATION_NOTIFICATION(CharacterDataWillChange, aContent,
+  IMPL_MUTATION_NOTIFICATION(CharacterDataWillChange, aContent,
                              (doc, aContent, aInfo));
 }