Use new is*Element() helper functions more in rendering code

Source/core/rendering/RenderMenuList.cpp

Index: Source/core/rendering/RenderMenuList.cpp
diff --git a/Source/core/rendering/RenderMenuList.cpp b/Source/core/rendering/RenderMenuList.cpp
index e64583ce17ad58d11a657ae8ed62be9ec6af7d13..5b28b71bb3d84b4cd73f0abdc16aae52d9144f0c 100644
--- a/Source/core/rendering/RenderMenuList.cpp
+++ b/Source/core/rendering/RenderMenuList.cpp
@@ -61,9 +61,7 @@ RenderMenuList::RenderMenuList(Element* element)
     , m_lastActiveIndex(-1)
     , m_popupIsVisible(false)
 {
-    ASSERT(element);
-    ASSERT(element->isHTMLElement());
-    ASSERT(element->hasTagName(HTMLNames::selectTag));
+    ASSERT(isHTMLSelectElement(element));
 }
 
 RenderMenuList::~RenderMenuList()
@@ -170,7 +168,7 @@ void RenderMenuList::updateOptionsWidth()
 
     for (int i = 0; i < size; ++i) {
         HTMLElement* element = listItems[i];
-        if (!element->hasTagName(optionTag))
+        if (!isHTMLOptionElement(*element))
             continue;
 
         String text = toHTMLOptionElement(element)->textIndentedToRespectGroupLabel();
@@ -219,7 +217,7 @@ void RenderMenuList::setTextFromOption(int optionIndex)
     String text = emptyString();
     if (i >= 0 && i < size) {
         Element* element = listItems[i];
-        if (element->hasTagName(optionTag)) {
+        if (isHTMLOptionElement(*element)) {
             text = toHTMLOptionElement(element)->textIndentedToRespectGroupLabel();
             m_optionStyle = element->renderStyle();
         }
@@ -395,10 +393,10 @@ String RenderMenuList::itemText(unsigned listIndex) const
 
     String itemString;
     Element* element = listItems[listIndex];
-    if (element->hasTagName(optgroupTag))
-        itemString = toHTMLOptGroupElement(element)->groupLabelText();
-    else if (element->hasTagName(optionTag))
-        itemString = toHTMLOptionElement(element)->textIndentedToRespectGroupLabel();
+    if (isHTMLOptGroupElement(*element))
+        itemString = toHTMLOptGroupElement(*element).groupLabelText();
+    else if (isHTMLOptionElement(*element))
+        itemString = toHTMLOptionElement(*element).textIndentedToRespectGroupLabel();
 
     applyTextTransform(style(), itemString, ' ');
     return itemString;
@@ -427,12 +425,12 @@ bool RenderMenuList::itemIsEnabled(unsigned listIndex) const
     if (listIndex >= listItems.size())
         return false;
     HTMLElement* element = listItems[listIndex];
-    if (!element->hasTagName(optionTag))
+    if (!isHTMLOptionElement(*element))
         return false;
 
     bool groupEnabled = true;
     if (Element* parentElement = element->parentElement()) {
-        if (parentElement->hasTagName(optgroupTag))
+        if (isHTMLOptGroupElement(*parentElement))
             groupEnabled = !parentElement->isDisabledFormControl();
     }
     if (!groupEnabled)
@@ -545,13 +543,13 @@ void RenderMenuList::popupDidHide()
 bool RenderMenuList::itemIsSeparator(unsigned listIndex) const
 {
     const Vector<HTMLElement*>& listItems = selectElement()->listItems();
-    return listIndex < listItems.size() && listItems[listIndex]->hasTagName(hrTag);
+    return listIndex < listItems.size() && isHTMLHRElement(*listItems[listIndex]);
 }
 
 bool RenderMenuList::itemIsLabel(unsigned listIndex) const
 {
     const Vector<HTMLElement*>& listItems = selectElement()->listItems();
-    return listIndex < listItems.size() && listItems[listIndex]->hasTagName(optgroupTag);
+    return listIndex < listItems.size() && isHTMLOptGroupElement(*listItems[listIndex]);
 }
 
 bool RenderMenuList::itemIsSelected(unsigned listIndex) const
@@ -560,7 +558,7 @@ bool RenderMenuList::itemIsSelected(unsigned listIndex) const
     if (listIndex >= listItems.size())
         return false;
     HTMLElement* element = listItems[listIndex];
-    return element->hasTagName(optionTag) && toHTMLOptionElement(element)->selected();
+    return isHTMLOptionElement(*element) && toHTMLOptionElement(*element).selected();
 }
 
 void RenderMenuList::setTextFromItem(unsigned listIndex)