--- a/js/xpconnect/loader/ChromeScriptLoader.cpp
+++ b/js/xpconnect/loader/ChromeScriptLoader.cpp
@@ -15,16 +15,17 @@
 #include "jsfriendapi.h"
 #include "js/Utility.h"
 
 #include "mozilla/dom/ChromeUtils.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/ScriptLoader.h"
 #include "mozilla/HoldDropJSObjects.h"
 #include "mozilla/SystemGroup.h"
+#include "nsCCUncollectableMarker.h"
 #include "nsCycleCollectionParticipant.h"
 
 using namespace JS;
 using namespace mozilla;
 using namespace mozilla::dom;
 
 class AsyncScriptCompiler final : public nsIIncrementalStreamLoaderObserver
                                 , public Runnable
@@ -333,16 +334,24 @@ PrecompiledScript::HasReturnValue()
 }
 
 JSObject*
 PrecompiledScript::WrapObject(JSContext* aCx, HandleObject aGivenProto)
 {
     return PrecompiledScriptBinding::Wrap(aCx, this, aGivenProto);
 }
 
+bool
+PrecompiledScript::IsBlackForCC(bool aTracingNeeded)
+{
+    return (nsCCUncollectableMarker::sGeneration &&
+            HasKnownLiveWrapper() &&
+            (!aTracingNeeded || HasNothingToTrace(this)));
+}
+
 NS_IMPL_CYCLE_COLLECTION_CLASS(PrecompiledScript)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PrecompiledScript)
     NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
     NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(PrecompiledScript)
@@ -356,13 +365,28 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(
     NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
 NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(PrecompiledScript)
     NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mScript)
     NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER
 NS_IMPL_CYCLE_COLLECTION_TRACE_END
 
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(PrecompiledScript)
+    if (tmp->IsBlackForCC(false)) {
+        tmp->mScript.exposeToActiveJS();
+        return true;
+    }
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(PrecompiledScript)
+    return tmp->IsBlackForCC(true);
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END
+
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(PrecompiledScript)
+    return tmp->IsBlackForCC(false);
+NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END
+
 NS_IMPL_CYCLE_COLLECTING_ADDREF(PrecompiledScript)
 NS_IMPL_CYCLE_COLLECTING_RELEASE(PrecompiledScript)
 
 } // namespace dom
 } // namespace mozilla

--- a/js/xpconnect/loader/PrecompiledScript.h
+++ b/js/xpconnect/loader/PrecompiledScript.h
@@ -17,17 +17,17 @@
 #include "nsWrapperCache.h"
 
 namespace mozilla {
 namespace dom {
 class PrecompiledScript : public nsISupports
                         , public nsWrapperCache
 {
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
-  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(PrecompiledScript)
+  NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(PrecompiledScript)
 
   explicit PrecompiledScript(nsISupports* aParent, JS::Handle<JSScript*> aScript, JS::ReadOnlyCompileOptions& aOptions);
 
   void ExecuteInGlobal(JSContext* aCx, JS::HandleObject aGlobal,
                        JS::MutableHandleValue aRval,
                        ErrorResult& aRv);
 
   void GetUrl(nsAString& aUrl);
@@ -38,16 +38,18 @@ class PrecompiledScript : public nsISupp
 
   virtual JSObject* WrapObject(JSContext* aCx,
                                JS::Handle<JSObject*> aGivenProto) override;
 
 protected:
   virtual ~PrecompiledScript();
 
 private:
+  bool IsBlackForCC(bool aTracingNeeded);
+
   nsCOMPtr<nsISupports> mParent;
 
   JS::Heap<JSScript*> mScript;
   nsCString mURL;
   const bool mHasReturnValue;
 };
 
 } // namespace dom