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

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

Index: third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp b/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
index eeedfe7e0d7d5aceab040af5ea114e5c1f5e344b..eedbc7b62fff703c72969e5c3166a724c56beff5 100644
--- a/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintInvalidator.cpp
@@ -11,6 +11,7 @@
 #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"
@@ -235,6 +236,12 @@ void PaintInvalidator::updatePaintingLayer(const LayoutObject& object,
   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();