Use Length for baselineShiftValue in SVGLayoutStyle

Source/core/animation/StringKeyframe.cpp

Index: Source/core/animation/StringKeyframe.cpp
diff --git a/Source/core/animation/StringKeyframe.cpp b/Source/core/animation/StringKeyframe.cpp
index dc9438e01db591f8debfffa48e622ca271e46c26..e146041d508aef07a822538c1c72e0444f5825ba 100644
--- a/Source/core/animation/StringKeyframe.cpp
+++ b/Source/core/animation/StringKeyframe.cpp
@@ -177,6 +177,7 @@ PassRefPtrWillBeRawPtr<Interpolation> StringKeyframe::PropertySpecificKeyframe::
     case CSSPropertyWidth:
         range = RangeNonNegative;
         // Fall through
+    case CSSPropertyBaselineShift:
     case CSSPropertyBottom:
     case CSSPropertyLeft:
     case CSSPropertyLetterSpacing:
@@ -200,6 +201,10 @@ PassRefPtrWillBeRawPtr<Interpolation> StringKeyframe::PropertySpecificKeyframe::
         if (property == CSSPropertyFontSize)
             fallBackToLegacy = true;
 
+        // FIXME: Handle keywords e.g. 'baseline', 'sub'.
+        if (property == CSSPropertyBaselineShift)
+            fallBackToLegacy = true;
+
         // FIXME: Handle keywords e.g. 'normal'
         if (property == CSSPropertyLetterSpacing)
             fallBackToLegacy = true;
@@ -329,7 +334,6 @@ PassRefPtrWillBeRawPtr<Interpolation> StringKeyframe::PropertySpecificKeyframe::
     case CSSPropertyStrokeWidth:
         range = RangeNonNegative;
         // Fall through
-    case CSSPropertyBaselineShift:
     case CSSPropertyStrokeDashoffset: {
         RefPtrWillBeRawPtr<Interpolation> interpolation = SVGLengthStyleInterpolation::maybeCreate(*fromCSSValue, *toCSSValue, property, range);
         if (interpolation)