Paint local background colors onto foreground layer.

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

Index: third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
index 58a6e0af7fa78625423459c75e00e5de63f499e1..017c4adb05795b677645d89a4fa52db4a0739eae 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerPainter.cpp
@@ -381,7 +381,9 @@ PaintLayerPainter::PaintResult PaintLayerPainter::paintLayerContents(GraphicsCon
             scopedPaintChunkProperties.emplace(context.getPaintController(), m_paintLayer, properties);
         }
 
-        bool shouldPaintBackground = isPaintingCompositedBackground && shouldPaintContent && !selectionOnly;
+        bool isPaintingRootLayer = (&m_paintLayer) == paintingInfo.rootLayer;
+        bool shouldPaintBackground = shouldPaintContent && !selectionOnly
+            && (isPaintingCompositedBackground || (isPaintingRootLayer && !(paintFlags & PaintLayerPaintingSkipRootBackground)));

[chrishtr, 2016/08/05 00:40:08]

Do you need isPaintingCompositedBackground now?

[flackr, 2016/08/08 18:01:30]

Yes, we still need to call paintBackgroundForFragments on
isPaintingCompositedBackground whether or not we are going to paint the actual
background in order to paint the borders, box shadow, etc.

         bool shouldPaintNegZOrderList = (isPaintingScrollingContent && isPaintingOverflowContents) || (!isPaintingScrollingContent && isPaintingCompositedBackground);
         bool shouldPaintOwnContents = isPaintingCompositedForeground && shouldPaintContent;
         bool shouldPaintNormalFlowAndPosZOrderLists = isPaintingCompositedForeground;