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

third_party/WebKit/Source/core/css/resolver/StyleResolverState.cpp

Index: third_party/WebKit/Source/core/css/resolver/StyleResolverState.cpp
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleResolverState.cpp b/third_party/WebKit/Source/core/css/resolver/StyleResolverState.cpp
index 4693d2393ce3aa1cb938353bb1e2206995ee6bca..a7c6edb5d19f00f609fe8fe7975f4dd1411063c1 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolverState.cpp
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolverState.cpp
@@ -114,14 +114,14 @@ void StyleResolverState::setCustomPropertySetForApplyAtRule(
 
 StylePropertySet* StyleResolverState::customPropertySetForApplyAtRule(
     const String& string) {
-  return m_customPropertySetsForApplyAtRule.get(string);
+  return m_customPropertySetsForApplyAtRule.at(string);
 }
 
 HeapHashMap<CSSPropertyID, Member<const CSSValue>>&
 StyleResolverState::parsedPropertiesForPendingSubstitutionCache(
     const CSSPendingSubstitutionValue& value) const {
   HeapHashMap<CSSPropertyID, Member<const CSSValue>>* map =
-      m_parsedPropertiesForPendingSubstitutionCache.get(&value);
+      m_parsedPropertiesForPendingSubstitutionCache.at(&value);
   if (!map) {
     map = new HeapHashMap<CSSPropertyID, Member<const CSSValue>>;
     m_parsedPropertiesForPendingSubstitutionCache.set(&value, map);