Fix Chromium issue 47824.

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 175 matching lines @@
 // They might invoke garbage collection. The result is an handle to
 // an object of expected type, or the handle is an error if running out
 // of space or encountering an internal error.
 
 void NormalizeProperties(Handle<JSObject> object,
                          PropertyNormalizationMode mode,
                          int expected_additional_properties);
 void NormalizeElements(Handle<JSObject> object);
 void TransformToFastProperties(Handle<JSObject> object,
                                int unused_property_fields);
+
+// 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> SetProperty(Handle<JSObject> object,
                            Handle<String> key,
                            Handle<Object> value,
                            PropertyAttributes attributes);
 
 Handle<Object> SetProperty(Handle<Object> object,
                            Handle<Object> key,
                            Handle<Object> value,
                            PropertyAttributes attributes);
 
@@ skipping 170 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_