Fix border radius on composited children.

third_party/WebKit/Source/core/paint/PaintLayer.h

Index: third_party/WebKit/Source/core/paint/PaintLayer.h
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.h b/third_party/WebKit/Source/core/paint/PaintLayer.h
index edda077fb96ec4880e7e43775f5cbeca25063792..438773f23413646831aa78e11b6d0d87dce7263f 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.h
@@ -835,6 +835,7 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
   LayoutRect paintingExtent(const PaintLayer* rootLayer,
                             const LayoutSize& subPixelAccumulation,
                             GlobalPaintFlags);
+
   void appendSingleFragmentIgnoringPagination(
       PaintLayerFragments&,
       const PaintLayer* rootLayer,
@@ -842,6 +843,7 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
       ClipRectsCacheSlot,
       OverlayScrollbarClipBehavior = IgnoreOverlayScrollbarSize,
       ShouldRespectOverflowClipType = RespectOverflowClip,
+      bool paintingAncestorClippingMask = false,

[Stephen Chennney, 2016/11/08 21:42:52]

I'm trying to get rid of this extra arg. It's hackish.

       const LayoutPoint* offsetFromRoot = 0,
       const LayoutSize& subPixelAccumulation = LayoutSize());
   void collectFragments(
@@ -851,6 +853,7 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
       ClipRectsCacheSlot,
       OverlayScrollbarClipBehavior = IgnoreOverlayScrollbarSize,
       ShouldRespectOverflowClipType = RespectOverflowClip,
+      bool paintingAncestorClippingMask = false,
       const LayoutPoint* offsetFromRoot = 0,
       const LayoutSize& subPixelAccumulation = LayoutSize(),
       const LayoutRect* layerBoundingBox = 0);