Add AX attribute for input type

Source/core/accessibility/AXNodeObject.cpp

Index: Source/core/accessibility/AXNodeObject.cpp
diff --git a/Source/core/accessibility/AXNodeObject.cpp b/Source/core/accessibility/AXNodeObject.cpp
index 34c1230cd4d494dc4864058f43f7edffccbb22fe..957705226bc274955751a9512f20a57e42c00f2c 100644
--- a/Source/core/accessibility/AXNodeObject.cpp
+++ b/Source/core/accessibility/AXNodeObject.cpp
@@ -1041,6 +1041,20 @@ String AXNodeObject::stringValue() const
     return String();
 }
 
+
+const AtomicString& AXNodeObject::textInputType() const
+{
+    Node* node = this->node();
+    if (!isHTMLInputElement(node))
+        return nullAtom;
+
+    HTMLInputElement& input = toHTMLInputElement(*node);
+    if (input.type() == InputTypeNames::tel || input.type() == InputTypeNames::url

[dglazkov, 2014/10/01 04:37:11]

Should this just be input.isTextField()?

[je_julie(Not used), 2014/10/01 04:53:52]

I'm referencing to implementation from FireFox for this.
https://bugzilla.mozilla.org/show_bug.cgi?id=924896
They handle text input type with just tel, url, email and search because it's
worthy of exporting to attribute.
If we use isTextField(), it includes email, password, search, tel, text, and URL
types.
Do we need to include all of them? 

[dmazzoni, 2014/10/01 05:22:57]

I think isTextField is probably more correct. Search and Password seem useful to
return too, and plus that's probably more future-proof if more are added later.

If one of them is not allowed to be returned on a particular platform, let's
handle it there.

+        || input.type() == InputTypeNames::email || input.type() == InputTypeNames::search)
+        return input.type();
+    return nullAtom;
+}
+
 String AXNodeObject::ariaDescribedByAttribute() const
 {
     WillBeHeapVector<RawPtrWillBeMember<Element> > elements;