Eagerly parse expected transitions in JSON.

src/objects.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 1750 matching lines @@
       PropertyAttributes attributes,
       StrictModeFlag strict_mode,
       ExtensibilityCheck extensibility_check);
 
   static Handle<Object> SetLocalPropertyIgnoreAttributes(
       Handle<JSObject> object,
       Handle<Name> key,
       Handle<Object> value,
       PropertyAttributes attributes);
 
+  static inline Handle<String> ExpectedTransitionKey(Handle<Map> map);
+  static inline Handle<Map> ExpectedTransitionTarget(Handle<Map> map);
+
   // Try to follow an existing transition to a field with attributes NONE. The
   // return value indicates whether the transition was successful.
-  static inline bool TryTransitionToField(Handle<JSObject> object,
-                                          Handle<Name> key);
+  static inline Handle<Map> FindTransitionToField(Handle<Map> map,
+                                                  Handle<Name> key);
 
   inline int LastAddedFieldIndex();
 
   // Extend the receiver with a single fast property appeared first in the
   // passed map. This also extends the property backing store if necessary.
   static void AddFastPropertyUsingMap(Handle<JSObject> object, Handle<Map> map);
   inline MUST_USE_RESULT MaybeObject* AddFastPropertyUsingMap(Map* map);
+  static void TransitionToMap(Handle<JSObject> object, Handle<Map> map);
+  inline MUST_USE_RESULT MaybeObject* TransitionToMap(Map* map);
 
   // Can cause GC.
   MUST_USE_RESULT MaybeObject* SetLocalPropertyIgnoreAttributes(
       Name* key,
       Object* value,
       PropertyAttributes attributes);
 
   // Retrieve a value in a normalized object given a lookup result.
   // Handles the special representation of JS global objects.
   Object* GetNormalizedProperty(LookupResult* result);
@@ skipping 3443 matching lines @@
                                                Descriptor* descriptor);
   MUST_USE_RESULT MaybeObject* CopyAddDescriptor(Descriptor* descriptor,
                                                  TransitionFlag flag);
   MUST_USE_RESULT MaybeObject* CopyInsertDescriptor(Descriptor* descriptor,
                                                     TransitionFlag flag);
   MUST_USE_RESULT MaybeObject* CopyReplaceDescriptor(
       DescriptorArray* descriptors,
       Descriptor* descriptor,
       int index,
       TransitionFlag flag);
+  MUST_USE_RESULT MaybeObject* AsElementsKind(ElementsKind kind);
   MUST_USE_RESULT MaybeObject* CopyAsElementsKind(ElementsKind kind,
                                                   TransitionFlag flag);
 
   MUST_USE_RESULT MaybeObject* CopyNormalized(PropertyNormalizationMode mode,
                                               NormalizedMapSharingMode sharing);
 
   inline void AppendDescriptor(Descriptor* desc,
                                const DescriptorArray::WhitenessWitness&);
 
   // Returns a copy of the map, with all transitions dropped from the
@@ skipping 4059 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_