Introduce toHTMLInputElement(Node*), and use it.

Source/core/accessibility/AccessibilityNodeObject.cpp

Index: Source/core/accessibility/AccessibilityNodeObject.cpp
diff --git a/Source/core/accessibility/AccessibilityNodeObject.cpp b/Source/core/accessibility/AccessibilityNodeObject.cpp
index b4e81226c12c4d81df31649b764341781bc4600f..0e71ec4bb4cf7276650956b890207a3a5614147c 100644
--- a/Source/core/accessibility/AccessibilityNodeObject.cpp
+++ b/Source/core/accessibility/AccessibilityNodeObject.cpp
@@ -78,7 +78,7 @@ static String accessibleNameForNode(Node* node)
         return toText(node)->data();
 
     if (node->hasTagName(inputTag))
-        return static_cast<HTMLInputElement*>(node)->value();
+        return toHTMLInputElement(node)->value();
 
     if (node->isHTMLElement()) {
         const AtomicString& alt = toHTMLElement(node)->getAttribute(altAttr);
@@ -183,7 +183,7 @@ AccessibilityRole AccessibilityNodeObject::determineAccessibilityRole()
     if (node()->hasTagName(buttonTag))
         return buttonRoleType();
     if (node()->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node());
+        HTMLInputElement* input = toHTMLInputElement(node());
         if (input->isCheckbox())
             return CheckBoxRole;
         if (input->isRadioButton())
@@ -533,10 +533,8 @@ bool AccessibilityNodeObject::isInputImage() const
     if (!node)
         return false;
 
-    if (roleValue() == ButtonRole && node->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
-        return input->isImageButton();
-    }
+    if (roleValue() == ButtonRole && node->hasTagName(inputTag))
+        return toHTMLInputElement(node)->isImageButton();
 
     return false;
 }
@@ -615,10 +613,8 @@ bool AccessibilityNodeObject::isNativeImage() const
     if (node->hasTagName(appletTag) || node->hasTagName(embedTag) || node->hasTagName(objectTag))
         return true;
 
-    if (node->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
-        return input->isImageButton();
-    }
+    if (node->hasTagName(inputTag))
+        return toHTMLInputElement(node)->isImageButton();
 
     return false;
 }
@@ -633,7 +629,7 @@ bool AccessibilityNodeObject::isNativeTextControl() const
         return true;
 
     if (node->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
+        HTMLInputElement* input = toHTMLInputElement(node);
         return input->isText() || input->isNumberField();
     }
 
@@ -773,7 +769,7 @@ bool AccessibilityNodeObject::isReadOnly() const
         return static_cast<HTMLTextAreaElement*>(node)->isReadOnly();
 
     if (node->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
+        HTMLInputElement* input = toHTMLInputElement(node);
         if (input->isTextField())
             return input->isReadOnly();
     }
@@ -936,7 +932,7 @@ void AccessibilityNodeObject::colorValue(int& r, int& g, int& b) const
     if (!node() || !node()->hasTagName(inputTag))
         return;
 
-    HTMLInputElement* input = static_cast<HTMLInputElement*>(node());
+    HTMLInputElement* input = toHTMLInputElement(node());
     const AtomicString& type = input->getAttribute(typeAttr);
     if (!equalIgnoringCase(type, "color"))
         return;
@@ -959,7 +955,7 @@ String AccessibilityNodeObject::valueDescription() const
 float AccessibilityNodeObject::valueForRange() const
 {
     if (node() && node()->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node());
+        HTMLInputElement* input = toHTMLInputElement(node());
         if (input->isRangeControl())
             return input->valueAsNumber();
     }
@@ -973,7 +969,7 @@ float AccessibilityNodeObject::valueForRange() const
 float AccessibilityNodeObject::maxValueForRange() const
 {
     if (node() && node()->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node());
+        HTMLInputElement* input = toHTMLInputElement(node());
         if (input->isRangeControl())
             return input->maximum();
     }
@@ -987,7 +983,7 @@ float AccessibilityNodeObject::maxValueForRange() const
 float AccessibilityNodeObject::minValueForRange() const
 {
     if (node() && node()->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node());
+        HTMLInputElement* input = toHTMLInputElement(node());
         if (input->isRangeControl())
             return input->minimum();
     }
@@ -1207,7 +1203,7 @@ String AccessibilityNodeObject::title() const
 
     bool isInputTag = node->hasTagName(inputTag);
     if (isInputTag) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
+        HTMLInputElement* input = toHTMLInputElement(node);
         if (input->isTextButton())
             return input->valueWithDefault();
     }
@@ -1458,7 +1454,7 @@ Element* AccessibilityNodeObject::actionElement() const
         return 0;
 
     if (node->hasTagName(inputTag)) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
+        HTMLInputElement* input = toHTMLInputElement(node);
         if (!input->isDisabledFormControl() && (isCheckboxOrRadio() || input->isTextButton()))
             return input;
     } else if (node->hasTagName(buttonTag))
@@ -1735,7 +1731,7 @@ void AccessibilityNodeObject::visibleText(Vector<AccessibilityText>& textOrder)
 
     bool isInputTag = node->hasTagName(inputTag);
     if (isInputTag) {
-        HTMLInputElement* input = static_cast<HTMLInputElement*>(node);
+        HTMLInputElement* input = toHTMLInputElement(node);
         if (input->isTextButton()) {
             textOrder.append(AccessibilityText(input->valueWithDefault(), VisibleText));
             return;