Have DocumentOrderedMap API deal with AtomicString type instead of StringImpl*

Source/core/dom/TreeScope.cpp

Index: Source/core/dom/TreeScope.cpp
diff --git a/Source/core/dom/TreeScope.cpp b/Source/core/dom/TreeScope.cpp
index 821cd6ede346ab06555e03502c92233ff02f023a..781e7b0d26cb9927c9411f4c77b79d766113d0c4 100644
--- a/Source/core/dom/TreeScope.cpp
+++ b/Source/core/dom/TreeScope.cpp
@@ -165,7 +165,7 @@ Element* TreeScope::getElementById(const AtomicString& elementId) const
         return 0;
     if (!m_elementsById)
         return 0;
-    return m_elementsById->getElementById(elementId.impl(), this);
+    return m_elementsById->getElementById(elementId, this);
 }
 
 const WillBeHeapVector<RawPtrWillBeMember<Element> >& TreeScope::getAllElementsById(const AtomicString& elementId) const
@@ -175,14 +175,14 @@ const WillBeHeapVector<RawPtrWillBeMember<Element> >& TreeScope::getAllElementsB
         return *emptyVector;
     if (!m_elementsById)
         return *emptyVector;
-    return m_elementsById->getAllElementsById(elementId.impl(), this);
+    return m_elementsById->getAllElementsById(elementId, this);
 }
 
 void TreeScope::addElementById(const AtomicString& elementId, Element* element)
 {
     if (!m_elementsById)
         m_elementsById = DocumentOrderedMap::create();
-    m_elementsById->add(elementId.impl(), element);
+    m_elementsById->add(elementId, element);
     m_idTargetObserverRegistry->notifyObservers(elementId);
 }
 
@@ -190,7 +190,7 @@ void TreeScope::removeElementById(const AtomicString& elementId, Element* elemen
 {
     if (!m_elementsById)
         return;
-    m_elementsById->remove(elementId.impl(), element);
+    m_elementsById->remove(elementId, element);
     m_idTargetObserverRegistry->notifyObservers(elementId);
 }
 
@@ -210,7 +210,7 @@ Node* TreeScope::ancestorInThisScope(Node* node) const
 
 void TreeScope::addImageMap(HTMLMapElement* imageMap)
 {
-    StringImpl* name = imageMap->getName().impl();
+    const AtomicString& name = imageMap->getName();
     if (!name)
         return;
     if (!m_imageMapsByName)
@@ -222,7 +222,7 @@ void TreeScope::removeImageMap(HTMLMapElement* imageMap)
 {
     if (!m_imageMapsByName)
         return;
-    StringImpl* name = imageMap->getName().impl();
+    const AtomicString& name = imageMap->getName();
     if (!name)
         return;
     m_imageMapsByName->remove(name, imageMap);
@@ -235,10 +235,10 @@ HTMLMapElement* TreeScope::getImageMap(const String& url) const
     if (!m_imageMapsByName)
         return 0;
     size_t hashPos = url.find('#');
-    String name = (hashPos == kNotFound ? url : url.substring(hashPos + 1)).impl();
+    String name = hashPos == kNotFound ? url : url.substring(hashPos + 1);
     if (rootNode().document().isHTMLDocument())
-        return toHTMLMapElement(m_imageMapsByName->getElementByLowercasedMapName(AtomicString(name.lower()).impl(), this));
-    return toHTMLMapElement(m_imageMapsByName->getElementByMapName(AtomicString(name).impl(), this));
+        return toHTMLMapElement(m_imageMapsByName->getElementByLowercasedMapName(AtomicString(name.lower()), this));
+    return toHTMLMapElement(m_imageMapsByName->getElementByMapName(AtomicString(name), this));
 }
 
 HitTestResult hitTestInDocument(const Document* document, int x, int y)
@@ -281,13 +281,13 @@ Element* TreeScope::elementFromPoint(int x, int y) const
 void TreeScope::addLabel(const AtomicString& forAttributeValue, HTMLLabelElement* element)
 {
     ASSERT(m_labelsByForAttribute);
-    m_labelsByForAttribute->add(forAttributeValue.impl(), element);
+    m_labelsByForAttribute->add(forAttributeValue, element);
 }
 
 void TreeScope::removeLabel(const AtomicString& forAttributeValue, HTMLLabelElement* element)
 {
     ASSERT(m_labelsByForAttribute);
-    m_labelsByForAttribute->remove(forAttributeValue.impl(), element);
+    m_labelsByForAttribute->remove(forAttributeValue, element);
 }
 
 HTMLLabelElement* TreeScope::labelElementForId(const AtomicString& forAttributeValue)
@@ -305,7 +305,7 @@ HTMLLabelElement* TreeScope::labelElementForId(const AtomicString& forAttributeV
         }
     }
 
-    return toHTMLLabelElement(m_labelsByForAttribute->getElementByLabelForAttribute(forAttributeValue.impl(), this));
+    return toHTMLLabelElement(m_labelsByForAttribute->getElementByLabelForAttribute(forAttributeValue, this));
 }
 
 DOMSelection* TreeScope::getSelection() const