Migrate WTF::HashMap::get() to ::at()

third_party/WebKit/Source/core/css/CSSStyleRule.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * (C) 2002-2003 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2002, 2005, 2006, 2008, 2012 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.
  *
@@ skipping 48 matching lines @@
     if (selector != m_styleRule->selectorList().first())
       builder.append(", ");
     builder.append(selector->selectorText());
   }
   return builder.toString();
 }
 
 String CSSStyleRule::selectorText() const {
   if (hasCachedSelectorText()) {
     ASSERT(selectorTextCache().contains(this));
-    return selectorTextCache().get(this);
+    return selectorTextCache().at(this);
   }
 
   ASSERT(!selectorTextCache().contains(this));
   String text = generateSelectorText();
   selectorTextCache().set(this, text);
   setHasCachedSelectorText(true);
   return text;
 }
 
 void CSSStyleRule::setSelectorText(const String& selectorText) {
@@ skipping 40 matching lines @@
   CSSRule::trace(visitor);
 }
 
 DEFINE_TRACE_WRAPPERS(CSSStyleRule) {
   visitor->traceWrappers(parentRule());
   visitor->traceWrappers(parentStyleSheet());
   CSSRule::traceWrappers(visitor);
 }
 
 }  // namespace blink