--- a/js/xpconnect/idl/xpccomponents.idl
+++ b/js/xpconnect/idl/xpccomponents.idl
@@ -245,16 +245,17 @@ interface nsIXPCComponents_Utils : nsISu
     [implicit_jscontext]
     xpcIJSWeakReference getWeakReference(in jsval obj);
 
     /*
      * To be called from JS only.
      *
      * Force an immediate garbage collection cycle.
      */
+    [implicit_jscontext]
     void forceGC();
 
     /*
      * To be called from JS only.
      *
      * Force an immediate cycle collection cycle.
      */
     void forceCC([optional] in nsICycleCollectorListener aListener);
@@ -299,16 +300,17 @@ interface nsIXPCComponents_Utils : nsISu
      */
     void clearMaxCCTime();
 
     /*
      * To be called from JS only.
      *
      * Force an immediate shrinking garbage collection cycle.
      */
+    [implicit_jscontext]
     void forceShrinkingGC();
 
     /*
      * Schedule a garbage collection cycle for a point in the future when no JS
      * is running. Call the provided function once this has occurred.
      */
     void schedulePreciseGC(in nsIScheduledGCCallback callback);
 

--- a/js/xpconnect/src/XPCComponents.cpp
+++ b/js/xpconnect/src/XPCComponents.cpp
@@ -1613,20 +1613,19 @@ nsXPCComponents_Utils::GetWeakReference(
   RefPtr<xpcJSWeakReference> ref = new xpcJSWeakReference();
   nsresult rv = ref->Init(cx, object);
   NS_ENSURE_SUCCESS(rv, rv);
   ref.forget(_retval);
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsXPCComponents_Utils::ForceGC() {
-  JSContext* cx = XPCJSContext::Get()->Context();
-  PrepareForFullGC(cx);
-  NonIncrementalGC(cx, GC_NORMAL, GCReason::COMPONENT_UTILS);
+nsXPCComponents_Utils::ForceGC(JSContext* aCx) {
+  PrepareForFullGC(aCx);
+  NonIncrementalGC(aCx, GC_NORMAL, GCReason::COMPONENT_UTILS);
   return NS_OK;
 }
 
 NS_IMETHODIMP
 nsXPCComponents_Utils::ForceCC(nsICycleCollectorListener* listener) {
   nsJSContext::CycleCollectNow(listener);
   return NS_OK;
 }
@@ -1659,20 +1658,19 @@ nsXPCComponents_Utils::GetMaxCCSliceTime
 
 NS_IMETHODIMP
 nsXPCComponents_Utils::ClearMaxCCTime() {
   nsJSContext::ClearMaxCCSliceTime();
   return NS_OK;
 }
 
 NS_IMETHODIMP
-nsXPCComponents_Utils::ForceShrinkingGC() {
-  JSContext* cx = dom::danger::GetJSContext();
-  PrepareForFullGC(cx);
-  NonIncrementalGC(cx, GC_SHRINK, GCReason::COMPONENT_UTILS);
+nsXPCComponents_Utils::ForceShrinkingGC(JSContext* aCx) {
+  PrepareForFullGC(aCx);
+  NonIncrementalGC(aCx, GC_SHRINK, GCReason::COMPONENT_UTILS);
   return NS_OK;
 }
 
 class PreciseGCRunnable : public Runnable {
  public:
   PreciseGCRunnable(nsIScheduledGCCallback* aCallback, bool aShrinking)
       : mozilla::Runnable("PreciseGCRunnable"),
         mCallback(aCallback),