Use unified invalidation path for repaint-only style changes

Source/core/rendering/RenderObject.cpp

Index: Source/core/rendering/RenderObject.cpp
diff --git a/Source/core/rendering/RenderObject.cpp b/Source/core/rendering/RenderObject.cpp
index 4db5c5918070ac914af0f20b1068121555da0b79..e46ec13718e17d829f1b5ee3280ae45b40f3b357 100644
--- a/Source/core/rendering/RenderObject.cpp
+++ b/Source/core/rendering/RenderObject.cpp
@@ -2059,15 +2059,14 @@ void RenderObject::setStyle(PassRefPtr<RenderStyle> style)
             container->setNeedsOverflowRecalcAfterStyleChange();
     }
 
-    if (updatedDiff.needsRepaint()) {
-        // Invalidate paints with the new style, e.g., for example if we go from not having
-        // an outline to having an outline.
-
-        // The paintInvalidationForWholeRenderer() call is needed for non-layout changes to style. See the corresponding
-        // comment in RenderObject::styleWillChange for why.
-        if (needsLayout())
+    if (updatedDiff.needsRepaintLayer()) {
+        toRenderLayerModelObject(this)->layer()->setShouldDoFullPaintInvalidationIncludingNonCompositingDescendants();
+    } else if (updatedDiff.needsRepaint()) {
+        // FIXME: For objects whose invalidateTreeIfNeeded won't invalidate themselves,
+        // we still need to invalidate now. crbug.com/394133.
+        if (needsLayout() || canSelfInvalidateDuringTreeInvalidation())
             setShouldDoFullPaintInvalidation(true);
-        else if (!selfNeedsLayout())
+        else
             paintInvalidationForWholeRenderer();
     }
 }
@@ -2103,12 +2102,14 @@ void RenderObject::styleWillChange(StyleDifference diff, const RenderStyle& newS
             }
         }
 
-        // For style-only changes that need paint invalidation, we currently need to issue a paint invalidation before and after the style
-        // change. The paint invalidation before style change is accomplished here. The paint invalidation after style change is accomplished
-        // in RenderObject::setStyle.
         if (m_parent && diff.needsRepaintObject()) {
-            if (!diff.needsLayout() && !needsLayout())
-                paintInvalidationForWholeRenderer();
+            if (!diff.needsLayout() && !needsLayout()) {
+                // Invalidate before style change.
+                // FIXME: See FIXMEs in setStyle() before calling paintInvalidationForWholeRenderer
+                // for the reason of this paintInvalidationForWholeRenderer.
+                if (!canSelfInvalidateDuringTreeInvalidation())
+                    paintInvalidationForWholeRenderer();
+            }
         }
 
         if (isFloating() && (m_style->floating() != newStyle.floating()))