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

third_party/WebKit/Source/core/html/HTMLCollection.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2014 Samsung Electronics. 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
@@ skipping 105 matching lines @@
   DECLARE_VIRTUAL_TRACE();
 
  protected:
   HTMLCollection(ContainerNode& base, CollectionType, ItemAfterOverrideType);
 
   class NamedItemCache final : public GarbageCollected<NamedItemCache> {
    public:
     static NamedItemCache* create() { return new NamedItemCache; }
 
     HeapVector<Member<Element>>* getElementsById(const AtomicString& id) const {
-      return m_idCache.get(id.impl());
+      return m_idCache.at(id.impl());
     }
     HeapVector<Member<Element>>* getElementsByName(
         const AtomicString& name) const {
-      return m_nameCache.get(name.impl());
+      return m_nameCache.at(name.impl());
     }
     void addElementWithId(const AtomicString& id, Element* element) {
       addElementToMap(m_idCache, id, element);
     }
     void addElementWithName(const AtomicString& name, Element* element) {
       addElementToMap(m_nameCache, name, element);
     }
 
     DEFINE_INLINE_TRACE() {
       visitor->trace(m_idCache);
@@ skipping 79 matching lines @@
   if (!attrName ||
       shouldInvalidateTypeOnAttributeChange(invalidationType(), *attrName))
     invalidateCache();
   else if (*attrName == HTMLNames::idAttr || *attrName == HTMLNames::nameAttr)
     invalidateIdNameCacheMaps();
 }
 
 }  // namespace blink
 
 #endif  // HTMLCollection_h