Improve default value handling for SVGSVGElement.width/height

third_party/WebKit/Source/core/svg/SVGAnimatedLength.cpp

Index: third_party/WebKit/Source/core/svg/SVGAnimatedLength.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGAnimatedLength.cpp b/third_party/WebKit/Source/core/svg/SVGAnimatedLength.cpp
index ddbb866d35e3ba6436d344f6f96faee2078ffdd4..991ddd45e211b6d66862acb0a684b5891cd068a0 100644
--- a/third_party/WebKit/Source/core/svg/SVGAnimatedLength.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGAnimatedLength.cpp
@@ -34,6 +34,11 @@
 
 namespace blink {
 
+void SVGAnimatedLength::setDefaultValue()
+{
+    setDefaultValueAsString(m_defaultValue);
+}
+
 void SVGAnimatedLength::setDefaultValueAsString(const String& value)
 {
     baseValue()->setValueAsString(value);
@@ -41,10 +46,15 @@ void SVGAnimatedLength::setDefaultValueAsString(const String& value)
 
 SVGParsingError SVGAnimatedLength::setBaseValueAsString(const String& value)
 {
+    if (value.isNull()) {
+        setDefaultValue();
+        return SVGParseStatus::NoError;
+    }
+
     SVGParsingError parseStatus = baseValue()->setValueAsString(value);
 
     if (parseStatus != SVGParseStatus::NoError)
-        baseValue()->newValueSpecifiedUnits(CSSPrimitiveValue::UnitType::UserUnits, 0);
+        setDefaultValue();
     else if (SVGLength::negativeValuesForbiddenForAnimatedLengthAttribute(attributeName()) && baseValue()->valueInSpecifiedUnits() < 0)
         parseStatus = SVGParseStatus::NegativeValue;