Paint backgrounds of a table section/row in one display item

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

 // Copyright 2016 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/PaintInvalidator.h"
 
 #include "core/editing/FrameSelection.h"
 #include "core/frame/FrameView.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutBlockFlow.h"
 #include "core/layout/LayoutObject.h"
 #include "core/layout/LayoutTable.h"
+#include "core/layout/LayoutTableSection.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/svg/SVGLayoutSupport.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintLayer.h"
 #include "core/paint/PaintLayerScrollableArea.h"
 #include "core/paint/PaintPropertyTreeBuilder.h"
 #include "wtf/Optional.h"
 
 namespace blink {
 
@@ skipping 204 matching lines @@
   if (object.isTable()) {
     const LayoutTable& table = toLayoutTable(object);
     if (table.collapseBorders() && !table.collapsedBorders().isEmpty())
       context.paintingLayer->setNeedsPaintPhaseDescendantBlockBackgrounds();
   }
 
   // The following flags are for descendants of the layer object only.
   if (object == context.paintingLayer->layoutObject())
     return;
 
+  if (object.isTableSection()) {

[chrishtr, 2017/03/31 22:59:06]

This seems a weird place to invalidate paint phases.

[Xianzhu, 2017/03/31 23:26:30]

This is to update paint phase requirements of layers. Would you prefer moving
these code into layout classes implementing something like
LayoutObject::updatePaintingLayerPaintPhaseRequirements()?

[chrishtr, 2017/04/03 17:10:51]

Yes, that makes more sense, thanks.

+    const auto& section = toLayoutTableSection(object);
+    if (section.table()->hasColElements())

[wkorman, 2017/03/31 22:15:41]

If we change for prior comment would need to follow here similarly.

+      context.paintingLayer->setNeedsPaintPhaseDescendantBlockBackgrounds();
+  }
+
   if (object.styleRef().hasOutline())
     context.paintingLayer->setNeedsPaintPhaseDescendantOutlines();
 
   if (object.hasBoxDecorationBackground()
       // We also paint overflow controls in background phase.
       || (object.hasOverflowClip() &&
           toLayoutBox(object).getScrollableArea()->hasOverflowControls())) {
     context.paintingLayer->setNeedsPaintPhaseDescendantBlockBackgrounds();
   }
 }
@@ skipping 248 matching lines @@
   }
 }
 
 void PaintInvalidator::processPendingDelayedPaintInvalidations() {
   for (auto target : m_pendingDelayedPaintInvalidations)
     target->getMutableForPainting().setShouldDoFullPaintInvalidation(
         PaintInvalidationDelayedFull);
 }
 
 }  // namespace blink