Bug 1332233 - prevent resource leak in CustomElementRegistry::Define. r=baku

MozReview-Commit-ID: AzXgls3lKCA

--HG--
extra : rebase_source : 89c5c54e0c149aa01dd576fa66402eff1ac76173

dom/base/CustomElementRegistry.cpp

@@ -772,13 +772,6 @@ CustomElementRegistry::Define(const nsAString& aName,
   // Associate the definition with the custom element.
   nsCOMPtr<nsIAtom> localNameAtom(NS_Atomize(localName));
   LifecycleCallbacks* callbacks = callbacksHolder.forget();
-  CustomElementDefinition* definition =
-    new CustomElementDefinition(nameAtom,
-                                localNameAtom,
-                                constructor,
-                                constructorPrototype,
-                                callbacks,
-                                0 /* TODO dependent on HTML imports. Bug 877072 */);
 
   /**
    * 12. Add definition to this CustomElementRegistry.
@@ -788,6 +781,14 @@ CustomElementRegistry::Define(const nsAString& aName,
     return;
   }
 
+  CustomElementDefinition* definition =
+    new CustomElementDefinition(nameAtom,
+                                localNameAtom,
+                                constructor,
+                                constructorPrototype,
+                                callbacks,
+                                0 /* TODO dependent on HTML imports. Bug 877072 */);
+
   mCustomDefinitions.Put(nameAtom, definition);
 
   MOZ_ASSERT(mCustomDefinitions.Count() == mConstructors.count(),