Removing border attribute should remove the visual border

Source/core/html/HTMLElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004-2008, 2013, 2014 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2011 Motorola Mobility. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 109 matching lines @@
     if (element->hasTagName(preTag) || element->hasTagName(textareaTag))
         return CSSValueWebkitPlaintext;
     // FIXME: For bdo element, dir="auto" should result in "bidi-override isolate" but we don't support having multiple values in unicode-bidi yet.
     // See https://bugs.webkit.org/show_bug.cgi?id=73164.
     return CSSValueWebkitIsolate;
 }
 
 unsigned HTMLElement::parseBorderWidthAttribute(const AtomicString& value) const
 {
     unsigned borderWidth = 0;
-    if (value.isEmpty() || !parseHTMLNonNegativeInteger(value, borderWidth))
-        return hasTagName(tableTag) ? 1 : borderWidth;
+    if (value.isEmpty() || !parseHTMLNonNegativeInteger(value, borderWidth)) {
+        if (hasTagName(tableTag) && !value.isNull())
+            return 1;
+    }
     return borderWidth;
 }
 
 void HTMLElement::applyBorderAttributeToStyle(const AtomicString& value, MutableStylePropertySet* style)
 {
     addPropertyToPresentationAttributeStyle(style, CSSPropertyBorderWidth, parseBorderWidthAttribute(value), CSSPrimitiveValue::CSS_PX);
     addPropertyToPresentationAttributeStyle(style, CSSPropertyBorderStyle, CSSValueSolid);
 }
 
 void HTMLElement::mapLanguageAttributeToLocale(const AtomicString& value, MutableStylePropertySet* style)
@@ skipping 892 matching lines @@
 #ifndef NDEBUG
 
 // For use in the debugger
 void dumpInnerHTML(blink::HTMLElement*);
 
 void dumpInnerHTML(blink::HTMLElement* element)
 {
     printf("%s\n", element->innerHTML().ascii().data());
 }
 #endif