cc: Enable composited border-radius scrolling.

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.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@gmail.com>
@@ skipping 1903 matching lines @@
           MainThreadScrollingReason::kIsNotStackingContextAndLCDText;
     }
 
     needs_composited_scrolling = false;
   }
 
   // TODO(schenney) Tests fail if we do not also exclude
   // layer->layoutObject().style()->hasBorderDecoration() (missing background
   // behind dashed borders). Resolve this case, or not, and update this check
   // with the results.
-  if (layer->GetLayoutObject().Style()->HasBorderRadius()) {
-    non_composited_main_thread_scrolling_reasons_ |=
-        MainThreadScrollingReason::kHasBorderRadius;
-    needs_composited_scrolling = false;
-  }
   if (layer->GetLayoutObject().HasClip() ||
       layer->HasDescendantWithClipPath() || layer->HasAncestorWithClipPath()) {
     non_composited_main_thread_scrolling_reasons_ |=
         MainThreadScrollingReason::kHasClipRelatedProperty;
     needs_composited_scrolling = false;
   }
 
   DCHECK(!(non_composited_main_thread_scrolling_reasons_ &
            ~MainThreadScrollingReason::kNonCompositedReasons));
   return needs_composited_scrolling;
@@ skipping 271 matching lines @@
 
 void PaintLayerScrollableArea::DelayScrollOffsetClampScope::
     ClampScrollableAreas() {
   for (auto& scrollable_area : *needs_clamp_)
     scrollable_area->ClampScrollOffsetAfterOverflowChange();
   delete needs_clamp_;
   needs_clamp_ = nullptr;
 }
 
 }  // namespace blink