[Autofill/Autocomplete Feature] Substring matching instead of prefix matching (Blink).

Source/web/WebFormControlElement.cpp

Index: Source/web/WebFormControlElement.cpp
diff --git a/Source/web/WebFormControlElement.cpp b/Source/web/WebFormControlElement.cpp
index c02f22746b3a2a526bd8c456180361cd503ab958..666174dc8fe3d23a21178dd2f1a36185fe3407e7 100644
--- a/Source/web/WebFormControlElement.cpp
+++ b/Source/web/WebFormControlElement.cpp
@@ -180,6 +180,23 @@ WebFormElement WebFormControlElement::form() const
     return WebFormElement(constUnwrap<HTMLFormControlElement>()->form());
 }
 
+void WebFormControlElement::setSuggestedValueStart(int start)
+{
+    if (isHTMLInputElement(*m_private))
+        unwrap<HTMLInputElement>()->setSuggestedValueStart(start);
+    if (isHTMLTextAreaElement(*m_private))
+        unwrap<HTMLTextAreaElement>()->setSuggestedValueStart(start);
+}
+
+int WebFormControlElement::suggestedValueStart() const
+{
+    if (isHTMLInputElement(*m_private))
+        return constUnwrap<HTMLInputElement>()->suggestedValueStart();
+    if (isHTMLTextAreaElement(*m_private))
+        return constUnwrap<HTMLTextAreaElement>()->suggestedValueStart();
+    return 0;
+}
+
 WebFormControlElement::WebFormControlElement(const PassRefPtrWillBeRawPtr<HTMLFormControlElement>& elem)
     : WebElement(elem)
 {