Remove multicol special-cases from invalidation and the pre-paint tree walk

third_party/WebKit/Source/core/paint/PrePaintTreeWalk.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/PrePaintTreeWalk.h"
 
 #include "core/dom/DocumentLifecycle.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/layout/LayoutMultiColumnSpannerPlaceholder.h"
@@ skipping 84 matching lines @@
   if (object.hasOverflowClip() || (paintLayer && paintLayer->isRootLayer())) {
     DCHECK(paintLayer);
     context.ancestorOverflowPaintLayer = paintLayer;
   }
 }
 
 bool PrePaintTreeWalk::walk(const LayoutObject& object,
                             const PrePaintTreeWalkContext& parentContext) {
   PrePaintTreeWalkContext context(parentContext);
 
-  // TODO(pdr): Ensure multi column works with incremental property tree
-  // construction.
-  if (object.isLayoutMultiColumnSpannerPlaceholder()) {
-    // Walk multi-column spanner as if it replaces the placeholder.
-    // Set the flag so that the tree builder can specially handle out-of-flow
-    // positioned descendants if their containers are between the multi-column
-    // container and the spanner. See PaintPropertyTreeBuilder for details.
-    context.treeBuilderContext.isUnderMultiColumnSpanner = true;
-    const auto& placeholder = toLayoutMultiColumnSpannerPlaceholder(object);
-    bool descendantsFullyUpdated =
-        walk(*placeholder.layoutObjectInFlowThread(), context);
-    if (descendantsFullyUpdated) {
-      // If descendants were not fully updated, do not clear flags. During the
-      // next PrePaintTreeWalk, these flags will be used again.
-      object.getMutableForPainting().clearPaintFlags();
-    }
-    return descendantsFullyUpdated;
-  }
-
   // This must happen before updateContextForBoxPosition, because the
   // latter reads some of the state computed uere.
   updateAuxiliaryObjectProperties(object, context);
 
   // Ensure the current context takes into account the box's position. This can
   // force a subtree update due to paint offset changes and must precede any
   // early out from the treewalk.
   LayoutPoint oldPaintOffset = object.paintOffset();
   m_propertyTreeBuilder.updateContextForBoxPosition(object,
                                                     context.treeBuilderContext);
@@ skipping 13 matching lines @@
   m_propertyTreeBuilder.updatePropertiesForSelf(object,
                                                 context.treeBuilderContext);
   m_paintInvalidator.invalidatePaintIfNeeded(object, oldPaintOffset,
                                              context.paintInvalidatorContext);
   m_propertyTreeBuilder.updatePropertiesForChildren(object,
                                                     context.treeBuilderContext);
 
   bool descendantsFullyUpdated = true;
   for (const LayoutObject* child = object.slowFirstChild(); child;
        child = child->nextSibling()) {
-    // Column spanners are walked through their placeholders. See above.
-    if (child->isColumnSpanAll())
+    if (child->isLayoutMultiColumnSpannerPlaceholder()) {
+      child->getMutableForPainting().clearPaintFlags();
       continue;
+    }
     bool childFullyUpdated = walk(*child, context);
     if (!childFullyUpdated)
       descendantsFullyUpdated = false;
   }
 
   if (object.isLayoutPart()) {
     const LayoutPart& layoutPart = toLayoutPart(object);
     Widget* widget = layoutPart.widget();
     if (widget && widget->isFrameView()) {
       context.treeBuilderContext.current.paintOffset +=
@@ skipping 10 matching lines @@
 
   if (descendantsFullyUpdated) {
     // If descendants were not updated, do not clear flags. During the next
     // PrePaintTreeWalk, these flags will be used again.
     object.getMutableForPainting().clearPaintFlags();
   }
   return descendantsFullyUpdated;
 }
 
 }  // namespace blink