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

third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp

Index: third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp b/third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp
index 3a4bf18879baaedeb302bda9eb6014d0ed1337bb..d0da8f9d15aaab907be54f4771757d618770f613 100644
--- a/third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutTableBoxComponent.cpp
@@ -25,4 +25,20 @@ bool LayoutTableBoxComponent::doCellsHaveDirtyWidth(
          !oldStyle.border().sizeEquals(tablePart.style()->border());
 }
 
+void LayoutTableBoxComponent::MutableForPainting::updatePaintResult(
+    PaintResult paintResult,
+    const CullRect& paintRect) {
+  // A table row or section may paint large background display item which
+  // contains paint operations of the background in each contained cell.
+  // The display item can be clipped by the paint rect to avoid painting
+  // on areas not interested. If we didn't fully paint and paint rect changes,
+  // we need to invalidate the display item.
+  auto& box = static_cast<LayoutTableBoxComponent&>(m_layoutObject);
+  if (box.m_lastPaintResult != FullyPainted && box.m_lastPaintRect != paintRect)
+    box.setDisplayItemsUncached();

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

Why this vs invalidateDisplayItemClient?

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

It should be invalidateDisplayItemClient. Done.

+
+  box.m_lastPaintResult = paintResult;
+  box.m_lastPaintRect = paintRect;
+}
+
 }  // namespace blink