Remove case-insensitive matching of usemap attribute.

third_party/WebKit/Source/core/dom/DocumentOrderedMap.cpp

Index: third_party/WebKit/Source/core/dom/DocumentOrderedMap.cpp
diff --git a/third_party/WebKit/Source/core/dom/DocumentOrderedMap.cpp b/third_party/WebKit/Source/core/dom/DocumentOrderedMap.cpp
index 4fdb2c418658d49f9d12a998c8b80a9ba4ca2db8..7cfb4ee738ac0aa612020a9495f8cb03b97a0cd4 100644
--- a/third_party/WebKit/Source/core/dom/DocumentOrderedMap.cpp
+++ b/third_party/WebKit/Source/core/dom/DocumentOrderedMap.cpp
@@ -75,12 +75,6 @@ inline bool keyMatchesSlotName(const AtomicString& key,
   return isHTMLSlotElement(element) && toHTMLSlotElement(element).name() == key;
 }
 
-inline bool keyMatchesLowercasedMapName(const AtomicString& key,
-                                        const Element& element) {
-  return isHTMLMapElement(element) &&
-         toHTMLMapElement(element).getName().lower() == key;
-}
-
 void DocumentOrderedMap::add(const AtomicString& key, Element* element) {
   DCHECK(key);
   DCHECK(element);
@@ -208,12 +202,6 @@ HTMLSlotElement* DocumentOrderedMap::getSlotByName(
   return nullptr;
 }
 
-Element* DocumentOrderedMap::getElementByLowercasedMapName(
-    const AtomicString& key,
-    const TreeScope* scope) const {
-  return get<keyMatchesLowercasedMapName>(key, scope);
-}
-
 DEFINE_TRACE(DocumentOrderedMap) {
   visitor->trace(m_map);
 }