Default value of |size| IDL attribute of HTMLSelectElement should be 0.

Source/core/html/HTMLSelectElement.cpp

Index: Source/core/html/HTMLSelectElement.cpp
diff --git a/Source/core/html/HTMLSelectElement.cpp b/Source/core/html/HTMLSelectElement.cpp
index d9e21145bcee7e21df0cd27ac6ce12e474cb5d6a..015a8812751d7e2facc25299a71bb46df48a788d 100644
--- a/Source/core/html/HTMLSelectElement.cpp
+++ b/Source/core/html/HTMLSelectElement.cpp
@@ -337,7 +337,7 @@ void HTMLSelectElement::parseAttribute(const QualifiedName& name, const AtomicSt
             if (Attribute* sizeAttribute = ensureUniqueElementData().attributes().find(sizeAttr))
                 sizeAttribute->setValue(attrSize);
         }
-        size = std::max(size, 1);
+        size = std::max(size, 0);
 
         // Ensure that we've determined selectedness of the items at least once prior to changing the size.
         if (oldSize != size)