Use ConstructFromLiteral instead of implicit conversion

Source/core/svg/SVGAnimatedAngle.cpp

Index: Source/core/svg/SVGAnimatedAngle.cpp
diff --git a/Source/core/svg/SVGAnimatedAngle.cpp b/Source/core/svg/SVGAnimatedAngle.cpp
index d074a7d30eebb2ab869d2d1c817ef9b9e4493953..dd338ddad944daa12c8896ab58e17d6b0b4e9dfe 100644
--- a/Source/core/svg/SVGAnimatedAngle.cpp
+++ b/Source/core/svg/SVGAnimatedAngle.cpp
@@ -49,9 +49,10 @@ SVGAnimatedAngle::~SVGAnimatedAngle()
 
 void SVGAnimatedAngle::synchronizeAttribute()
 {
+    DEFINE_STATIC_LOCAL(const AtomicString, autoValue, ("auto", AtomicString::ConstructFromLiteral));
     AtomicString value;
     if (m_orientType->currentValue()->enumValue() == SVGMarkerOrientAuto)
-        value = "auto";
+        value = autoValue;
     else
         value = AtomicString(currentValue()->valueAsString());