Support keywords in LengthStyleInterpolation

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..18779160d0b0360817b60000e5e5a37880df3519 100644
--- a/Source/core/animation/StringKeyframe.cpp
+++ b/Source/core/animation/StringKeyframe.cpp
@@ -190,23 +190,13 @@ PassRefPtrWillBeRawPtr<Interpolation> StringKeyframe::PropertySpecificKeyframe::
     case CSSPropertyVerticalAlign:
     case CSSPropertyWordSpacing:
     case CSSPropertyWebkitColumnRuleWidth:
-        if (LengthStyleInterpolation::canCreateFrom(*fromCSSValue) && LengthStyleInterpolation::canCreateFrom(*toCSSValue))
+        if (LengthStyleInterpolation::canCreateFrom(*fromCSSValue, property) && LengthStyleInterpolation::canCreateFrom(*toCSSValue, property))
             return LengthStyleInterpolation::create(*fromCSSValue, *toCSSValue, property, range);
 
-        // FIXME: Handle keywords e.g. 'none'.
-        if (property == CSSPropertyPerspective)
-            fallBackToLegacy = true;
         // FIXME: Handle keywords e.g. 'smaller', 'larger'.
         if (property == CSSPropertyFontSize)
             fallBackToLegacy = true;
 
-        // FIXME: Handle keywords e.g. 'normal'
-        if (property == CSSPropertyLetterSpacing)
-            fallBackToLegacy = true;
-
-        // FIXME: Handle keywords e.g. 'thick'
-        if (property == CSSPropertyOutlineWidth || property == CSSPropertyWebkitColumnRuleWidth)
-            fallBackToLegacy = true;
         break;
     case CSSPropertyOrphans:
     case CSSPropertyWidows: