Bug 994413 - Make Gecko use the same value marking semantics as SpiderMonkey; r=jonco,mccr8

dom/base/Console.cpp

@@ -507,9 +507,7 @@ NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(Console)
     }
 
     for (uint32_t i = 0; i < data->mArguments.Length(); ++i) {
-      if (JSVAL_IS_TRACEABLE(data->mArguments[i])) {
-        aCallbacks.Trace(&data->mArguments[i], "data->mArguments[i]", aClosure);
-      }
+      aCallbacks.Trace(&data->mArguments[i], "data->mArguments[i]", aClosure);
     }
   }
 

xpcom/base/nsCycleCollector.cpp

@@ -2411,9 +2411,11 @@ public:
     virtual void Trace(JS::Heap<JS::Value>* aValue, const char* aName,
                        void* aClosure) const
     {
-        void* thing = JSVAL_TO_TRACEABLE(aValue->get());
-        if (thing && xpc_GCThingIsGrayCCThing(thing)) {
-            mCollector->GetJSPurpleBuffer()->mValues.AppendElement(*aValue);
+        if (aValue->isMarkable()) {
+            void* thing = aValue->toGCThing();
+            if (thing && xpc_GCThingIsGrayCCThing(thing)) {
+                mCollector->GetJSPurpleBuffer()->mValues.AppendElement(*aValue);
+            }
         }
     }
 

xpcom/glue/nsCycleCollectionParticipant.cpp

@@ -69,7 +69,9 @@ CycleCollectionNoteEdgeNameImpl(nsCycleCollectionTraversalCallback& aCallback,
 void
 TraceCallbackFunc::Trace(JS::Heap<JS::Value>* p, const char* name, void* closure) const
 {
-  mCallback(JSVAL_TO_TRACEABLE(p->get()), name, closure);
+  if (p->isMarkable()) {
+    mCallback(p->toGCThing(), name, closure);
+  }
 }
 
 void

xpcom/glue/nsCycleCollectionParticipant.h

@@ -429,9 +429,7 @@ T* DowncastCCParticipant(void *p)
     aCallbacks.Trace(&tmp->_field, #_field, aClosure);
 
 #define NS_IMPL_CYCLE_COLLECTION_TRACE_JSVAL_MEMBER_CALLBACK(_field)           \
-  if (JSVAL_IS_TRACEABLE(tmp->_field)) {                                       \
-    aCallbacks.Trace(&tmp->_field, #_field, aClosure);                         \
-  }
+  aCallbacks.Trace(&tmp->_field, #_field, aClosure);
 
 // NB: The (void)tmp; hack in the TRACE_END macro exists to support
 // implementations that don't need to do anything in their Trace method.