Introduce toHTMLInputElement(Node*), and use it.

Source/core/html/shadow/TextControlInnerElements.cpp

Index: Source/core/html/shadow/TextControlInnerElements.cpp
diff --git a/Source/core/html/shadow/TextControlInnerElements.cpp b/Source/core/html/shadow/TextControlInnerElements.cpp
index fece33913683be57f8e9781b750b9479cf46a640..811f9944be3cb477471f9ecc2557974afb366164 100644
--- a/Source/core/html/shadow/TextControlInnerElements.cpp
+++ b/Source/core/html/shadow/TextControlInnerElements.cpp
@@ -156,7 +156,7 @@ const AtomicString& SearchFieldDecorationElement::shadowPseudoId() const
 void SearchFieldDecorationElement::defaultEventHandler(Event* event)
 {
     // On mousedown, focus the search field
-    HTMLInputElement* input = static_cast<HTMLInputElement*>(shadowHost());
+    HTMLInputElement* input = toHTMLInputElement(shadowHost());
     if (input && event->type() == eventNames().mousedownEvent && event->isMouseEvent() && static_cast<MouseEvent*>(event)->button() == LeftButton) {
         input->focus();
         input->select();
@@ -205,7 +205,7 @@ void SearchFieldCancelButtonElement::detach()
 void SearchFieldCancelButtonElement::defaultEventHandler(Event* event)
 {
     // If the element is visible, on mouseup, clear the value, and set selection
-    RefPtr<HTMLInputElement> input(static_cast<HTMLInputElement*>(shadowHost()));
+    RefPtr<HTMLInputElement> input(toHTMLInputElement(shadowHost()));
     if (!input || input->isDisabledOrReadOnly()) {
         if (!event->defaultHandled())
             HTMLDivElement::defaultEventHandler(event);
@@ -244,7 +244,7 @@ void SearchFieldCancelButtonElement::defaultEventHandler(Event* event)
 
 bool SearchFieldCancelButtonElement::willRespondToMouseClickEvents()
 {
-    const HTMLInputElement* input = static_cast<HTMLInputElement*>(shadowHost());
+    const HTMLInputElement* input = toHTMLInputElement(shadowHost());
     if (input && !input->isDisabledOrReadOnly())
         return true;
 
@@ -289,7 +289,7 @@ void InputFieldSpeechButtonElement::defaultEventHandler(Event* event)
     // The call to focus() below dispatches a focus event, and an event handler in the page might
     // remove the input element from DOM. To make sure it remains valid until we finish our work
     // here, we take a temporary reference.
-    RefPtr<HTMLInputElement> input(static_cast<HTMLInputElement*>(shadowHost()));
+    RefPtr<HTMLInputElement> input(toHTMLInputElement(shadowHost()));
 
     if (!input || input->isDisabledOrReadOnly()) {
         if (!event->defaultHandled())
@@ -341,7 +341,7 @@ void InputFieldSpeechButtonElement::defaultEventHandler(Event* event)
 
 bool InputFieldSpeechButtonElement::willRespondToMouseClickEvents()
 {
-    const HTMLInputElement* input = static_cast<HTMLInputElement*>(shadowHost());
+    const HTMLInputElement* input = toHTMLInputElement(shadowHost());
     if (input && !input->isDisabledOrReadOnly())
         return true;
 
@@ -378,7 +378,7 @@ void InputFieldSpeechButtonElement::setRecognitionResult(int, const SpeechInputR
     // The call to setValue() below dispatches an event, and an event handler in the page might
     // remove the input element from DOM. To make sure it remains valid until we finish our work
     // here, we take a temporary reference.
-    RefPtr<HTMLInputElement> input(static_cast<HTMLInputElement*>(shadowHost()));
+    RefPtr<HTMLInputElement> input(toHTMLInputElement(shadowHost()));
     if (!input || input->isDisabledOrReadOnly())
         return;
 
@@ -431,7 +431,7 @@ void InputFieldSpeechButtonElement::startSpeechInput()
     if (m_state != Idle)
         return;
 
-    RefPtr<HTMLInputElement> input = static_cast<HTMLInputElement*>(shadowHost());
+    RefPtr<HTMLInputElement> input = toHTMLInputElement(shadowHost());
     AtomicString language = input->computeInheritedLanguage();
     String grammar = input->getAttribute(webkitgrammarAttr);
     IntRect rect = document()->view()->contentsToRootView(pixelSnappedBoundingBox());