Separate repaint and layout requirements of StyleDifference (Step 1)

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 499b96bd978143addd22974e740573285d19a6a1..810cba22d524c91c17e359099d8b4686f6e4fd7b 100644
--- a/Source/core/rendering/style/RenderStyle.cpp
+++ b/Source/core/rendering/style/RenderStyle.cpp
@@ -366,7 +366,14 @@ static bool positionedObjectMovedOnly(const LengthBox& a, const LengthBox& b, co
     return true;
 }
 
-StyleDifference RenderStyle::visualInvalidationDiff(const RenderStyle& other, unsigned& changedContextSensitiveProperties) const
+StyleDifference RenderStyle::visualInvalidationDiff(const RenderStyle& other) const
+{
+    unsigned context = ContextSensitivePropertyNone;
+    StyleDifferenceLegacy diff = visualInvalidationDiffLegacy(other, context);
+    return StyleDifference(diff, context);
+}
+
+StyleDifferenceLegacy RenderStyle::visualInvalidationDiffLegacy(const RenderStyle& other, unsigned& changedContextSensitiveProperties) const
 {
     changedContextSensitiveProperties = ContextSensitivePropertyNone;
 
@@ -374,7 +381,7 @@ StyleDifference RenderStyle::visualInvalidationDiff(const RenderStyle& other, un
     // compare, which is duplicate work when we're going to compare each property inside
     // this function anyway.
 
-    StyleDifference svgChange = StyleDifferenceEqual;
+    StyleDifferenceLegacy svgChange = StyleDifferenceEqual;
     if (m_svgStyle.get() != other.m_svgStyle.get()) {
         svgChange = m_svgStyle->diff(other.m_svgStyle.get());
         if (svgChange == StyleDifferenceLayout)
@@ -593,12 +600,12 @@ StyleDifference RenderStyle::visualInvalidationDiff(const RenderStyle& other, un
         return StyleDifferenceLayout;
     }
 
-    StyleDifference repaintDifference = repaintOnlyDiff(other, changedContextSensitiveProperties);
+    StyleDifferenceLegacy repaintDifference = repaintOnlyDiff(other, changedContextSensitiveProperties);
     ASSERT(repaintDifference <= StyleDifferenceRepaintLayer);
     return repaintDifference;
 }
 
-StyleDifference RenderStyle::repaintOnlyDiff(const RenderStyle& other, unsigned& changedContextSensitiveProperties) const
+StyleDifferenceLegacy RenderStyle::repaintOnlyDiff(const RenderStyle& other, unsigned& changedContextSensitiveProperties) const
 {
     if (position() != StaticPosition && (m_box->zIndex() != other.m_box->zIndex() || m_box->hasAutoZIndex() != other.m_box->hasAutoZIndex()
         || visual->clip != other.visual->clip || visual->hasClip != other.visual->hasClip))