Add Autofill preview support for <select> input fields

Source/core/testing/Internals.cpp

Index: Source/core/testing/Internals.cpp
diff --git a/Source/core/testing/Internals.cpp b/Source/core/testing/Internals.cpp
index 65bd2e614f46fe1463efcd8805cd0b9aae2a3ed1..7d514da6a17ce30227eded8ab999885ed5633793 100644
--- a/Source/core/testing/Internals.cpp
+++ b/Source/core/testing/Internals.cpp
@@ -1013,6 +1013,10 @@ String Internals::suggestedValue(Element* element, ExceptionState& exceptionStat
 
     if (isHTMLTextAreaElement(*element))
         suggestedValue = toHTMLTextAreaElement(*element).suggestedValue();
+
+    if (isHTMLSelectElement(*element))
+        suggestedValue = toHTMLSelectElement(*element).suggestedValue();
+
     return suggestedValue;
 }
 
@@ -1033,6 +1037,9 @@ void Internals::setSuggestedValue(Element* element, const String& value, Excepti
 
     if (isHTMLTextAreaElement(*element))
         toHTMLTextAreaElement(*element).setSuggestedValue(value);
+
+    if (isHTMLSelectElement(*element))
+        toHTMLSelectElement(*element).setSuggestedValue(value);
 }
 
 void Internals::setEditingValue(Element* element, const String& value, ExceptionState& exceptionState)