Cleanup: Start using toFoo methods as part of newly adopted coding guideline.

Source/core/css/StyleInvalidationAnalysis.cpp

 /*
  * Copyright (C) 2012 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 131 matching lines @@
     }
 
     const Vector<RefPtr<StyleRuleBase> >& rules = styleSheetContents->childRules();
     for (unsigned i = 0; i < rules.size(); i++) {
         StyleRuleBase* rule = rules[i].get();
         if (!rule->isStyleRule()) {
             // FIXME: Media rules and maybe some others could be allowed.
             m_dirtiesAllStyle = true;
             return;
         }
-        StyleRule* styleRule = static_cast<StyleRule*>(rule);
+        StyleRule* styleRule = toStyleRule(rule);
         if (!determineSelectorScopes(styleRule->selectorList(), m_idScopes, m_classScopes)) {
             m_dirtiesAllStyle = true;
             return;
         }
     }
 }
 
 static bool elementMatchesSelectorScopes(const Element* element, const HashSet<StringImpl*>& idScopes, const HashSet<StringImpl*>& classScopes)
 {
     if (!idScopes.isEmpty() && element->hasID() && idScopes.contains(element->idForStyleResolution().impl()))
@@ skipping 25 matching lines @@
             element->setNeedsStyleRecalc();
             // The whole subtree is now invalidated, we can skip to the next sibling.
             element = ElementTraversal::nextSkippingChildren(element);
             continue;
         }
         element = ElementTraversal::next(element);
     }
 }
 
 }