[FastTextAutosizer] Remove comment about storing a fingerprint stack

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 517 matching lines @@
     return result;
 }
 
 FastTextAutosizer::Fingerprint FastTextAutosizer::computeFingerprint(const RenderObject* renderer)
 {
     Node* node = renderer->generatingNode();
     if (!node || !node->isElementNode())
         return 0;
 
     FingerprintSourceData data;
-
-    // FIXME: Instead of computing and caching parent fingerprints on demand,
-    // consider maintaining a fingerprint stack during the style recalc
-    // tree walk (similar to the cluster stack used during layout).
-
     if (const RenderObject* parent = parentElementRenderer(renderer))
         data.m_parentHash = getFingerprint(parent);
 
     data.m_qualifiedNameHash = QualifiedNameHash::hash(toElement(node)->tagQName());
 
     if (RenderStyle* style = renderer->style()) {
         data.m_packedStyleProperties = style->direction();
         data.m_packedStyleProperties |= (style->position() << 1);
         data.m_packedStyleProperties |= (style->floating() << 4);
         data.m_packedStyleProperties |= (style->display() << 6);
@@ skipping 378 matching lines @@
         m_textAutosizer = 0;
 }
 
 FastTextAutosizer::LayoutScope::~LayoutScope()
 {
     if (m_textAutosizer)
         m_textAutosizer->endLayout(m_block);
 }
 
 } // namespace WebCore