diff --git a/content/base/src/nsContentList.cpp b/content/base/src/nsContentList.cpp
index 7365c07bfe45..4900b1d13639 100644
--- a/content/base/src/nsContentList.cpp
+++ b/content/base/src/nsContentList.cpp
@@ -47,9 +47,9 @@
 #include "nsIDOMNode.h"
 #include "nsIDocument.h"
 #include "nsGenericElement.h"
-
+#include "nsWrapperCacheInlines.h"
 #include "nsContentUtils.h"
-
+#include "nsCCUncollectableMarker.h"
 #include "nsGkAtoms.h"
 
 #include "dombindings.h"
@@ -80,8 +80,11 @@ NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(nsBaseContentList)
   NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(nsBaseContentList)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSTARRAY_OF_NSCOMPTR(mElements)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE_SCRIPT_OBJECTS
+  if (nsCCUncollectableMarker::sGeneration && tmp->IsBlack()) {
+    return NS_SUCCESS_INTERRUPTED_TRAVERSE;
+  }
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSTARRAY_OF_NSCOMPTR(mElements)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(nsBaseContentList)
   NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
diff --git a/content/base/src/nsGenericElement.cpp b/content/base/src/nsGenericElement.cpp
index 49e7610c94d1..6f9e76ce17a5 100644
--- a/content/base/src/nsGenericElement.cpp
+++ b/content/base/src/nsGenericElement.cpp
@@ -1207,13 +1207,6 @@ nsINode::Trace(nsINode *tmp, TraceCallback cb, void *closure)
   nsContentUtils::TraceWrapper(tmp, cb, closure);
 }
 
-static bool
-IsBlackNode(nsINode* aNode)
-{
-  JSObject* o = aNode->GetWrapperPreserveColor();
-  return o && !xpc_IsGrayGCThing(o);
-}
-
 static bool
 IsXBL(nsINode* aNode)
 {
@@ -1233,7 +1226,7 @@ nsINode::Traverse(nsINode *tmp, nsCycleCollectionTraversalCallback &cb)
 
   if (nsCCUncollectableMarker::sGeneration) {
     // If we're black no need to traverse.
-    if (IsBlackNode(tmp)) {
+    if (tmp->IsBlack()) {
       return false;
     }
 
@@ -1246,13 +1239,13 @@ nsINode::Traverse(nsINode *tmp, nsCycleCollectionTraversalCallback &cb)
 
     if (!tmp->HasFlag(problematicFlags) && !IsXBL(tmp)) {
       // If we're in a black document, return early.
-      if ((currentDoc && IsBlackNode(currentDoc))) {
+      if ((currentDoc && currentDoc->IsBlack())) {
         return false;
       }
       // If we're not in anonymous content and we have a black parent,
       // return early.
       nsIContent* parent = tmp->GetParent();
-      if (parent && !IsXBL(parent) && IsBlackNode(parent)) {
+      if (parent && !IsXBL(parent) && parent->IsBlack()) {
         NS_ABORT_IF_FALSE(parent->IndexOf(tmp) >= 0, "Parent doesn't own us?");
         return false;
       }
diff --git a/dom/base/nsWrapperCache.h b/dom/base/nsWrapperCache.h
index e330f2fe3b44..a8f2f7c57e6d 100644
--- a/dom/base/nsWrapperCache.h
+++ b/dom/base/nsWrapperCache.h
@@ -190,6 +190,11 @@ public:
     return nsnull;
   }
 
+  /**
+   * Returns true if the object has a non-gray wrapper.
+   */
+  bool IsBlack();
+
 private:
   // Only meant to be called by nsContentUtils.
   void SetPreservingWrapper(bool aPreserve)
diff --git a/dom/base/nsWrapperCacheInlines.h b/dom/base/nsWrapperCacheInlines.h
index a1129e9ab2d9..ddd44cd91e94 100644
--- a/dom/base/nsWrapperCacheInlines.h
+++ b/dom/base/nsWrapperCacheInlines.h
@@ -139,4 +139,11 @@ nsWrapperCache::ClearWrapperIfProxy()
     SetWrapperBits(NULL);
 }
 
+inline bool
+nsWrapperCache::IsBlack()
+{
+  JSObject* o = GetWrapperPreserveColor();
+  return o && !xpc_IsGrayGCThing(o);
+}
+
 #endif /* nsWrapperCache_h___ */