Convert animation and renderer code to know about BorderImageLength

Source/core/rendering/style/RenderStyle.cpp

Index: Source/core/rendering/style/RenderStyle.cpp
diff --git a/Source/core/rendering/style/RenderStyle.cpp b/Source/core/rendering/style/RenderStyle.cpp
index 77a13f9912698bab095b746bf6b1c843be85e72b..2f92c96213b4f0e3075acac250ed33a58ce7b11b 100644
--- a/Source/core/rendering/style/RenderStyle.cpp
+++ b/Source/core/rendering/style/RenderStyle.cpp
@@ -1610,18 +1610,18 @@ void RenderStyle::setBorderImageSlices(LengthBox slices)
     surround.access()->border.m_image.setImageSlices(slices);
 }
 
-void RenderStyle::setBorderImageWidth(LengthBox slices)
+void RenderStyle::setBorderImageWidth(LengthOrNumberBox slices)
 {
-    if (surround->border.m_image.borderSlices().lengthBox() == slices)
+    if (surround->border.m_image.borderSlices() == slices)
         return;
-    surround.access()->border.m_image.setBorderSlices(LengthOrNumberBox(slices));
+    surround.access()->border.m_image.setBorderSlices(slices);
 }
 
-void RenderStyle::setBorderImageOutset(LengthBox outset)
+void RenderStyle::setBorderImageOutset(LengthOrNumberBox outset)
 {
-    if (surround->border.m_image.outset().lengthBox() == outset)
+    if (surround->border.m_image.outset() == outset)
         return;
-    surround.access()->border.m_image.setOutset(LengthOrNumberBox(outset));
+    surround.access()->border.m_image.setOutset(outset);
 }
 
 ShapeValue* RenderStyle::initialShapeInside()