Use words! closureFunc -> function, closureCtxt -> context.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 3314c72efe8a016b79b7350f1873ae1c91e2eb9d..6d8a27b62f46273e256c909697616732ddc98102 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -14144,10 +14144,8 @@ void Instance::PrintJSONImpl(JSONStream* stream, bool ref) const {
   PrintSharedInstanceJSON(&jsobj, ref);
   jsobj.AddServiceId("id", *this);
   if (IsClosure()) {
-    const Function& closureFunc = Function::Handle(Closure::function(*this));
-    jsobj.AddProperty("closureFunc", closureFunc);
-    const Context& closureCtxt = Context::Handle(Closure::context(*this));
-    jsobj.AddProperty("closureCtxt", closureCtxt);
+    jsobj.AddProperty("function", Function::Handle(Closure::function(*this)));
+    jsobj.AddProperty("context", Context::Handle(Closure::context(*this)));
   }
   if (ref) {
     return;