More cleanup related to setting array.length

src/elements.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ELEMENTS_H_
 #define V8_ELEMENTS_H_
 
 #include "src/elements-kind.h"
 #include "src/heap/heap.h"
 #include "src/isolate.h"
@@ skipping 56 matching lines @@
   inline MaybeHandle<AccessorPair> GetAccessorPair(Handle<JSObject> holder,
                                                    uint32_t key) {
     return GetAccessorPair(holder, key, handle(holder->elements()));
   }
 
   // Modifies the length data property as specified for JSArrays and resizes the
   // underlying backing store accordingly. The method honors the semantics of
   // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that
   // have non-deletable elements can only be shrunk to the size of highest
   // element that is non-deletable.
-  MUST_USE_RESULT virtual MaybeHandle<Object> SetLength(
-      Handle<JSArray> holder,
-      Handle<Object> new_length) = 0;
+  virtual void SetLength(Handle<JSArray> holder, uint32_t new_length) = 0;
 
   // Modifies both the length and capacity of a JSArray, resizing the underlying
   // backing store as necessary. This method does NOT honor the semantics of
   // EcmaScript 5.1 15.4.5.2, arrays can be shrunk beyond non-deletable
   // elements. This method should only be called for array expansion OR by
   // runtime JavaScript code that use InternalArrays and don't care about
   // EcmaScript 5.1 semantics.
   virtual void SetCapacityAndLength(
       Handle<JSArray> array,
       int capacity,
@@ skipping 98 matching lines @@
 void CheckArrayAbuse(Handle<JSObject> obj, const char* op, uint32_t key,
                      bool allow_appending = false);
 
 MUST_USE_RESULT MaybeHandle<Object> ArrayConstructInitializeElements(
     Handle<JSArray> array,
     Arguments* args);
 
 } }  // namespace v8::internal
 
 #endif  // V8_ELEMENTS_H_