Oilpan: Remove Document* pointers in objects

Source/core/rendering/FastTextAutosizer.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 1136 matching lines @@
     if (specifiedSize <= pleasantSize) {
         computedSize = multiplier * specifiedSize;
     } else {
         computedSize = multiplier * pleasantSize + gradientAfterPleasantSize * (specifiedSize - pleasantSize);
         if (computedSize < specifiedSize)
             computedSize = specifiedSize;
     }
     return computedSize;
 }
 
+void FastTextAutosizer::trace(Visitor* visitor)
+{
+    visitor->trace(m_document);
+}
+
 } // namespace blink