CSS Transforms: Implement backface-visibility

Source/core/css/CSSComputedStyleDeclaration.cpp

Index: Source/core/css/CSSComputedStyleDeclaration.cpp
diff --git a/Source/core/css/CSSComputedStyleDeclaration.cpp b/Source/core/css/CSSComputedStyleDeclaration.cpp
index 075537e09f8f55dc17828fb907a0e05b5492fb53..965fcad3ed2a1e8f93e1740596a2b4af986ce1f1 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.cpp
+++ b/Source/core/css/CSSComputedStyleDeclaration.cpp
@@ -221,6 +221,7 @@ static const CSSPropertyID staticComputableProperties[] = {
     CSSPropertyWebkitAnimationPlayState,
     CSSPropertyWebkitAnimationTimingFunction,
     CSSPropertyWebkitAppearance,
+    CSSPropertyBackfaceVisibility,
     CSSPropertyWebkitBackfaceVisibility,
     CSSPropertyWebkitBackgroundClip,
     CSSPropertyWebkitBackgroundComposite,
@@ -2465,6 +2466,7 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValu
             if (!style->hasAspectRatio())
                 return cssValuePool().createIdentifierValue(CSSValueNone);
             return CSSAspectRatioValue::create(style->aspectRatioNumerator(), style->aspectRatioDenominator());
+        case CSSPropertyBackfaceVisibility:
         case CSSPropertyWebkitBackfaceVisibility:
             return cssValuePool().createIdentifierValue((style->backfaceVisibility() == BackfaceVisibilityHidden) ? CSSValueHidden : CSSValueVisible);
         case CSSPropertyWebkitBorderImage:
@@ -2765,7 +2767,6 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValu
             break;
 
         // FIXME: crbug.com/154772 Unimplemented css-transforms properties
-        case CSSPropertyBackfaceVisibility:
         case CSSPropertyPerspective:
         case CSSPropertyPerspectiveOrigin:
         case CSSPropertyTransform: