Oilpan: fix build after r201639.

Source/core/css/ElementRuleCollector.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 44 matching lines @@
     const RuleData* ruleData() const { return m_ruleData; }
     uint64_t position() const { return m_position; }
     unsigned specificity() const { return ruleData()->specificity() + m_specificity; }
     const CSSStyleSheet* parentStyleSheet() const { return m_parentStyleSheet; }
     DEFINE_INLINE_TRACE()
     {
         visitor->trace(m_parentStyleSheet);
     }
 
 private:
-    RawPtrWillBeMember<const RuleData> m_ruleData;
+    // FIXME: Oilpan: RuleData is in the oilpan heap and this pointer
+    // really should be traced. However, RuleData objects are
+    // allocated inside larger TerminatedArray objects and we cannot
+    // trace a raw rule data pointer at this point.
+    const RuleData* m_ruleData;
     unsigned m_specificity;
     uint64_t m_position;
     RawPtrWillBeMember<const CSSStyleSheet> m_parentStyleSheet;
 };
 
 } // namespace blink
 
 WTF_ALLOW_MOVE_AND_INIT_WITH_MEM_FUNCTIONS(blink::MatchedRule);
 
 namespace blink {
@@ skipping 77 matching lines @@
 
     // Output.
     RefPtrWillBeMember<StaticCSSRuleList> m_cssRuleList;
     RefPtrWillBeMember<StyleRuleList> m_styleRuleList;
     MatchResult m_result;
 };
 
 } // namespace blink
 
 #endif // ElementRuleCollector_h