Return MaybeHandle from SetProperty.

src/handles.h

 // Copyright 2011 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 50 matching lines @@
   template <class S> MaybeHandle(MaybeHandle<S> maybe_handle) {
 #ifdef DEBUG
     T* a = NULL;
     S* b = NULL;
     a = b;  // Fake assignment to enforce type checks.
     USE(a);
 #endif
     location_ = reinterpret_cast<T**>(maybe_handle.location_);
   }
 
+  INLINE(void Assert()) { ASSERT(location_ != NULL); }
+  INLINE(void Check()) { CHECK(location_ != NULL); }
+
   INLINE(Handle<T> ToHandleChecked()) {
-    CHECK(location_ != NULL);
+    Check();
     return Handle<T>(location_);
   }
 
   // Convert to a Handle with a type that can be upcasted to.
   template <class S> INLINE(bool ToHandle(Handle<S>* out)) {
     if (location_ == NULL) {
       *out = Handle<T>::null();
       return false;
     } else {
       *out = Handle<T>(location_);
@@ skipping 201 matching lines @@
 // an object of expected type, or the handle is an error if running out
 // of space or encountering an internal error.
 
 // Flattens a string.
 void FlattenString(Handle<String> str);
 
 // Flattens a string and returns the underlying external or sequential
 // string.
 Handle<String> FlattenGetString(Handle<String> str);
 
-Handle<Object> ForceSetProperty(Handle<JSObject> object,
-                                Handle<Object> key,
-                                Handle<Object> value,
-                                PropertyAttributes attributes);
-
 Handle<Object> DeleteProperty(Handle<JSObject> object, Handle<Object> key);
 
 Handle<Object> ForceDeleteProperty(Handle<JSObject> object, Handle<Object> key);
 
 Handle<Object> HasProperty(Handle<JSReceiver> obj, Handle<Object> key);
 
 Handle<Object> GetProperty(Handle<JSReceiver> obj, const char* name);
 
 Handle<String> LookupSingleCharacterStringFromCode(Isolate* isolate,
                                                    uint32_t index);
@@ skipping 74 matching lines @@
 
   void Initialize() {
     next = limit = NULL;
     level = 0;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_H_