Clean up creation of "detached" SVG* data type objects

third_party/WebKit/Source/core/svg/SVGLengthTearOff.h

Index: third_party/WebKit/Source/core/svg/SVGLengthTearOff.h
diff --git a/third_party/WebKit/Source/core/svg/SVGLengthTearOff.h b/third_party/WebKit/Source/core/svg/SVGLengthTearOff.h
index 52439d570262cbd2836ed373939c98273b0be2c1..8bf94efdd0a7787dc39f469829a3b40592136997 100644
--- a/third_party/WebKit/Source/core/svg/SVGLengthTearOff.h
+++ b/third_party/WebKit/Source/core/svg/SVGLengthTearOff.h
@@ -57,14 +57,14 @@ class SVGLengthTearOff final : public SVGPropertyTearOff<SVGLength>,
     kSvgLengthtypePc = 10
   };
 
-  static SVGLengthTearOff* Create(
-      SVGLength* target,
-      SVGElement* context_element,
-      PropertyIsAnimValType property_is_anim_val,
-      const QualifiedName& attribute_name = QualifiedName::Null()) {
+  static SVGLengthTearOff* Create(SVGLength* target,
+                                  SVGElement* context_element,
+                                  PropertyIsAnimValType property_is_anim_val,
+                                  const QualifiedName& attribute_name) {
     return new SVGLengthTearOff(target, context_element, property_is_anim_val,
                                 attribute_name);
   }
+  static SVGLengthTearOff* CreateDetached();
 
   unsigned short unitType();
   SVGLengthMode UnitMode();
@@ -87,7 +87,7 @@ class SVGLengthTearOff final : public SVGPropertyTearOff<SVGLength>,
   SVGLengthTearOff(SVGLength*,
                    SVGElement* context_element,
                    PropertyIsAnimValType,
-                   const QualifiedName& attribute_name = QualifiedName::Null());
+                   const QualifiedName& attribute_name);
 };
 
 }  // namespace blink