Use Length for the stroke-dashoffset property in SVGLayoutStyle

Source/core/css/resolver/AnimatedStyleBuilder.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 471 matching lines @@
     case CSSPropertyStopColor:
         style->setStopColor(toAnimatableColor(value)->color());
         return;
     case CSSPropertyStopOpacity:
         style->setStopOpacity(clampTo<float>(toAnimatableDouble(value)->toDouble(), 0, 1));
         return;
     case CSSPropertyStrokeDasharray:
         style->setStrokeDashArray(toAnimatableStrokeDasharrayList(value)->toSVGLengthList());
         return;
     case CSSPropertyStrokeDashoffset:
-        style->setStrokeDashOffset(toAnimatableSVGLength(value)->toSVGLength());
+        style->setStrokeDashOffset(animatableValueToLength(value, state));
         return;
     case CSSPropertyStrokeMiterlimit:
         style->setStrokeMiterLimit(clampTo<float>(toAnimatableDouble(value)->toDouble(), 1));
         return;
     case CSSPropertyStrokeOpacity:
         style->setStrokeOpacity(clampTo<float>(toAnimatableDouble(value)->toDouble(), 0, 1));
         return;
     case CSSPropertyStroke:
         {
             const AnimatableSVGPaint* svgPaint = toAnimatableSVGPaint(value);
@@ skipping 135 matching lines @@
     case CSSPropertyRy:
         style->setRy(animatableValueToLength(value, state));
         return;
 
     default:
         ASSERT_NOT_REACHED();
     }
 }
 
 } // namespace blink