[Isolates] Merge (7083,7111] from bleeding_edge.

src/handles.h

 // Copyright 2006-2008 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 208 matching lines @@
                              Handle<String> key,
                              Handle<Object> value,
                              PropertyAttributes attributes = NONE);
 
 Handle<Object> SetPropertyWithInterceptor(Handle<JSObject> object,
                                           Handle<String> key,
                                           Handle<Object> value,
                                           PropertyAttributes attributes,
                                           StrictModeFlag strict_mode);
 
-Handle<Object> SetElement(Handle<JSObject> object,
-                          uint32_t index,
-                          Handle<Object> value,
-                          StrictModeFlag strict_mode);
+MUST_USE_RESULT Handle<Object> SetElement(Handle<JSObject> object,
+                                          uint32_t index,
+                                          Handle<Object> value,
+                                          StrictModeFlag strict_mode);
 
 Handle<Object> SetOwnElement(Handle<JSObject> object,
                              uint32_t index,
                              Handle<Object> value,
                              StrictModeFlag strict_mode);
 
 Handle<Object> GetProperty(Handle<JSObject> obj,
                            const char* name);
 
 Handle<Object> GetProperty(Handle<Object> obj,
@@ skipping 136 matching lines @@
  private:
   bool has_been_transformed_;  // Tells whether the object has been transformed.
   int unused_property_fields_;  // Captures the unused number of field.
   Handle<JSObject> object_;    // The object being optimized.
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HANDLES_H_