Compute rounded-ness of visual rects

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 408 matching lines @@
         ancestorOverflowClip)
       destinationPropertyTreeState.setClip(ancestorOverflowClip);
   }
 
   // The background rect applies all clips *above* m_layer, but not the overflow
   // clip of m_layer. It also applies a clip to the total painting bounds
   // of m_layer, because nothing in m_layer or its children within the clip can
   // paint outside of those bounds.
   // The total painting bounds includes any visual overflow (such as shadow) and
   // filter bounds.
+  //
+  // TODO(chrishtr): sourceToDestinationVisualRect and
+  // sourceToDestinationClipRect may not compute tight results in the presence
+  // of transforms. Tight results are required for most use cases of these
+  // rects, so we should add methods to GeometryMapper that guarantee there
+  // are tight results, or else signal an error.
   if (shouldClipOverflow(context)) {
-    FloatRect clipRect(localVisualRect());
+    FloatClipRect clipRect((FloatRect(localVisualRect())));
     clipRect.moveBy(FloatPoint(m_layer.layoutObject().paintOffset()));
     GeometryMapper::sourceToDestinationVisualRect(
         sourcePropertyTreeState, destinationPropertyTreeState, clipRect);
-    output.setRect(FloatClipRect(clipRect));
+    output.setRect(clipRect);
   } else {
     const FloatClipRect& clippedRectInRootLayerSpace =
         GeometryMapper::sourceToDestinationClipRect(
             sourcePropertyTreeState, destinationPropertyTreeState);
     output.setRect(clippedRectInRootLayerSpace);
   }
 
   output.moveBy(-context.rootLayer->layoutObject().paintOffset());
 }
 
@@ skipping 167 matching lines @@
   DCHECK(!m_useGeometryMapper);
   ClipRectsContext context(rootLayer, PaintingClipRects,
                            IgnorePlatformOverlayScrollbarSize,
                            subpixelAccumulation);
   if (respectOverflowClip == IgnoreOverflowClip)
     context.setIgnoreOverflowClip();
   return getClipRects(context);
 }
 
 }  // namespace blink