Separate repaint and layout requirements of StyleDifference (Step 1)

Source/core/rendering/RenderLayerModelObject.cpp

Index: Source/core/rendering/RenderLayerModelObject.cpp
diff --git a/Source/core/rendering/RenderLayerModelObject.cpp b/Source/core/rendering/RenderLayerModelObject.cpp
index c413fd2466fd060d5c557839a9a922859af09942..38f807c884577e9398c504f8f02858e85bb9dfd0 100644
--- a/Source/core/rendering/RenderLayerModelObject.cpp
+++ b/Source/core/rendering/RenderLayerModelObject.cpp
@@ -98,35 +98,16 @@ void RenderLayerModelObject::styleWillChange(StyleDifference diff, const RenderS
     if (oldStyle) {
         // Do a repaint with the old style first through RenderLayerRepainter.
         // RenderObject::styleWillChange takes care of repainting objects without RenderLayers.
-        if (parent() && diff == StyleDifferenceRepaintLayer) {
+        if (parent() && diff.needsRepaintLayer()) {
             layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
             if (oldStyle->hasClip() != newStyle.hasClip()
                 || oldStyle->clip() != newStyle.clip())
                 layer()->clipper().clearClipRectsIncludingDescendants();
-        }
-
-        if (diff == StyleDifferenceLayout || diff == StyleDifferenceSimplifiedLayout) {

[eseidel, 2014/04/17 20:03:34]

Presumably this is the behavior change, correct?

-            // When a layout hint happens, we go ahead and do a repaint of the layer, since the layer could
-            // end up being destroyed.
-            if (hasLayer()) {
-                if (oldStyle->hasClip() != newStyle.hasClip()
-                    || oldStyle->clip() != newStyle.clip()) {
-                    // Composited layers don't need to be repainted when a parent's clip changes.
-                    layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
-                } else if (!layer()->hasCompositedLayerMapping()) {
-                    if (oldStyle->position() != newStyle.position()
-                        || oldStyle->zIndex() != newStyle.zIndex()
-                        || oldStyle->hasAutoZIndex() != newStyle.hasAutoZIndex()
-                        || oldStyle->opacity() != newStyle.opacity()
-                        || oldStyle->transform() != newStyle.transform()
-                        || oldStyle->filter() != newStyle.filter())
-                        layer()->repainter().repaintIncludingNonCompositingDescendants(containerForRepaint());
-                }
-            } else if (newStyle.hasTransform() || newStyle.opacity() < 1 || newStyle.hasFilter()) {
-                // If we don't have a layer yet, but we are going to get one because of transform or opacity,
-                //  then we need to repaint the old position of the object.
-                repaint();
-            }
+        } else if (!hasLayer() && diff.needsLayout()
+            && (newStyle.hasTransform() || newStyle.opacity() < 1 || newStyle.hasFilter())) {
+            // If we don't have a layer yet, but we are going to get one because of transform or opacity,
+            //  then we need to repaint the old position of the object.
+            repaint();
         }
     }