Bug 1184400, part 2 - XPCWrappedNative::Suspect() should suspect the JS reflector object even if it doesn't own it. r=bholley

js/xpconnect/src/XPCWrappedNative.cpp

@@ -104,7 +104,10 @@ XPCWrappedNative::Suspect(nsCycleCollectionNoteRootCallback& cb)
                "Suspecting wrapped natives from non-main thread");
 
     // Only record objects that might be part of a cycle as roots, unless
-    // the callback wants all traces (a debug feature).
+    // the callback wants all traces (a debug feature). Do this even if
+    // the XPCWN doesn't own the JS reflector object in case the reflector
+    // keeps alive other C++ things. This is safe because if the reflector
+    // had died the reference from the XPCWN to it would have been cleared.
     JSObject* obj = GetFlatJSObjectPreserveColor();
     if (JS::ObjectIsMarkedGray(obj) || cb.WantAllTraces())
         cb.NoteJSRoot(obj);

js/xpconnect/src/XPCWrappedNativeScope.cpp

@@ -497,10 +497,7 @@ XPCWrappedNativeScope::SuspectAllWrappers(XPCJSRuntime* rt,
 {
     for (XPCWrappedNativeScope* cur = gScopes; cur; cur = cur->mNext) {
         for (auto i = cur->mWrappedNativeMap->Iter(); !i.Done(); i.Next()) {
-            auto entry = static_cast<Native2WrappedNativeMap::Entry*>(i.Get());
-            XPCWrappedNative* wrapper = entry->value;
-            if (wrapper->HasExternalReference())
-                wrapper->Suspect(cb);
+            static_cast<Native2WrappedNativeMap::Entry*>(i.Get())->value->Suspect(cb);
         }
 
         if (cur->mDOMExpandoSet) {