Revert of [runtime] Do not use the enum-cache for non-prototype objects.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index b244c0e6a94e6b464d943874423653503103c525..429bd49c3399ec2d8bb620d1d46501ad840a1cf2 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -2284,6 +2284,9 @@
   inline void SetInternalField(int index, Object* value);
   inline void SetInternalField(int index, Smi* value);
 
+  void CollectOwnPropertyNames(KeyAccumulator* keys,
+                               PropertyFilter filter = ALL_PROPERTIES);
+
   // Returns the number of properties on this object filtering out properties
   // with the specified attributes (ignoring interceptors).
   // TODO(jkummerow): Deprecated, only used by Object.observe.
@@ -2293,15 +2296,12 @@
   // TODO(jkummerow): Deprecated, only used by Object.observe.
   int GetOwnElementKeys(FixedArray* storage, PropertyFilter filter);
 
-  void CollectOwnPropertyKeys(
-      KeyAccumulator* keys, PropertyFilter filter = ALL_PROPERTIES,
-      JSReceiver::KeyCollectionType type = JSReceiver::OWN_ONLY);
-
   static void CollectOwnElementKeys(Handle<JSObject> object,
                                     KeyAccumulator* keys,
                                     PropertyFilter filter);
-  static Handle<FixedArray> GetOwnEnumPropertyKeys(Handle<JSObject> object,
-                                                   bool cache_result);
+
+  static Handle<FixedArray> GetEnumPropertyKeys(Handle<JSObject> object,
+                                                bool cache_result);
 
   // Returns a new map with all transitions dropped from the object's current
   // map and the ElementsKind set.
@@ -2554,9 +2554,6 @@
   MUST_USE_RESULT static Maybe<bool> SetPrototypeUnobserved(
       Handle<JSObject> object, Handle<Object> value, bool from_javascript,
       ShouldThrow should_throw);
-
-  void CollectFastPropertyKeysTo(KeyAccumulator* keys, PropertyFilter filter,
-                                 JSReceiver::KeyCollectionType type);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
 };