Remove various Heap* types.

sky/engine/core/html/imports/HTMLImportsController.cpp

 /*
  * Copyright (C) 2013 Google Inc. 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
@@ skipping 139 matching lines @@
     }
 
     return 0;
 }
 
 Document* HTMLImportsController::loaderDocumentAt(size_t i) const
 {
     return loaderAt(i)->document();
 }
 
-void HTMLImportsController::trace(Visitor* visitor)
-{
-    visitor->trace(m_root);
-    visitor->trace(m_loaders);
-    DocumentSupplement::trace(visitor);
-}
-
 } // namespace blink