Fix border radius on composited children.

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

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights
  * reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 327 matching lines @@
 
   LayoutPoint offset;
   if (offsetFromRoot)
     offset = *offsetFromRoot;
   else
     m_layer.convertToLayerCoords(context.rootLayer, offset);
   layerBounds = LayoutRect(offset, LayoutSize(m_layer.size()));
 
   // Update the clip rects that will be passed to child layers.
   if (shouldClipOverflow(context)) {
-    foregroundRect.intersect(
+    LayoutRect offsetOverflowClipRect =
         toLayoutBox(layoutObject)
-            .overflowClipRect(offset, context.overlayScrollbarClipBehavior));
+            .overflowClipRect(offset, context.overlayScrollbarClipBehavior);
+    foregroundRect.intersect(offsetOverflowClipRect);

[chrishtr, 2016/12/02 19:21:47]

Is this just increasing clarity?

[Stephen Chennney, 2016/12/07 21:39:38]

It was for debugging output. I've reverted it.

     if (layoutObject.styleRef().hasBorderRadius())
       foregroundRect.setHasRadius(true);
 
     // FIXME: Does not do the right thing with columns yet, since we don't yet
     // factor in the individual column boxes as overflow.
 
     // The LayoutView is special since its overflow clipping rect may be larger
     // than its box rect (crbug.com/492871).
     LayoutRect layerBoundsWithVisualOverflow =
         layoutObject.isLayoutView()
@@ skipping 191 matching lines @@
     const LayoutSize& subpixelAccumulation) const {
   DCHECK(!m_geometryMapper);
   ClipRectsContext context(rootLayer, PaintingClipRects,
                            IgnoreOverlayScrollbarSize, subpixelAccumulation);
   if (respectOverflowClip == IgnoreOverflowClip)
     context.setIgnoreOverflowClip();
   return getClipRects(context);
 }
 
 }  // namespace blink