Reduce copying of local data structures in GeometryMapper and PaintLayerClipper.

third_party/WebKit/Source/core/layout/compositing/CompositedLayerMapping.cpp

 /*
  * Copyright (C) 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 537 matching lines @@
   // behave as if it lives in an unclipped universe so it can prepaint, etc.
   // This means that we need to check if we are actually clipped before
   // setting up m_ancestorClippingLayer otherwise
   // updateAncestorClippingLayerGeometry will fail as the clip rect will be
   // infinite.
   // FIXME: this should use cached clip rects, but this sometimes give
   // inaccurate results (and trips the ASSERTS in PaintLayerClipper).
   ClipRectsContext clipRectsContext(compositingAncestor, UncachedClipRects,
                                     IgnoreOverlayScrollbarSize);
   clipRectsContext.setIgnoreOverflowClip();
-  LayoutRect unsnappedParentClipRect =
-      m_owningLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
-          .backgroundClipRect(clipRectsContext)
-          .rect();
-  IntRect parentClipRect = pixelSnappedIntRect(unsnappedParentClipRect);
+
+  ClipRect clipRect;
+  m_owningLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
+      .calculateBackgroundClipRect(clipRectsContext, clipRect);
+  IntRect parentClipRect = pixelSnappedIntRect(clipRect.rect());
   owningLayerIsClipped = parentClipRect != LayoutRect::infiniteIntRect();
 
   // TODO(schenney): CSS clips are not applied to composited children, and
   // should be via mask or by compositing the parent too.
   // https://bugs.chromium.org/p/chromium/issues/detail?id=615870
   DCHECK(clippingContainer->style());
   owningLayerIsMasked =
       owningLayerIsClipped && clippingContainer->style()->hasBorderRadius() &&
       !ancestorRoundedCornersWontClip(layoutObject(), *clippingContainer);
 }
@@ skipping 572 matching lines @@
 void CompositedLayerMapping::updateAncestorClippingLayerGeometry(
     const PaintLayer* compositingContainer,
     const IntPoint& snappedOffsetFromCompositedAncestor,
     IntPoint& graphicsLayerParentLocation) {
   if (!compositingContainer || !m_ancestorClippingLayer)
     return;
 
   ClipRectsContext clipRectsContext(compositingContainer,
                                     PaintingClipRectsIgnoringOverflowClip,
                                     IgnoreOverlayScrollbarSize);
-  IntRect parentClipRect = pixelSnappedIntRect(
-      m_owningLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
-          .backgroundClipRect(clipRectsContext)
-          .rect());
-  ASSERT(parentClipRect != LayoutRect::infiniteIntRect());
-  m_ancestorClippingLayer->setPosition(
-      FloatPoint(parentClipRect.location() - graphicsLayerParentLocation));
-  m_ancestorClippingLayer->setSize(FloatSize(parentClipRect.size()));
+
+  ClipRect parentClipRect;
+  m_owningLayer.clipper(PaintLayer::DoNotUseGeometryMapper)
+      .calculateBackgroundClipRect(clipRectsContext, parentClipRect);
+
+  IntRect snappedParentClipRect(pixelSnappedIntRect(parentClipRect.rect()));
+
+  DCHECK(snappedParentClipRect != LayoutRect::infiniteIntRect());
+  m_ancestorClippingLayer->setPosition(FloatPoint(
+      snappedParentClipRect.location() - graphicsLayerParentLocation));
+  m_ancestorClippingLayer->setSize(FloatSize(snappedParentClipRect.size()));
 
   // backgroundRect is relative to compositingContainer, so subtract
   // snappedOffsetFromCompositedAncestor.X/snappedOffsetFromCompositedAncestor.Y
   // to get back to local coords.
   m_ancestorClippingLayer->setOffsetFromLayoutObject(
-      parentClipRect.location() - snappedOffsetFromCompositedAncestor);
+      snappedParentClipRect.location() - snappedOffsetFromCompositedAncestor);
 
   if (m_ancestorClippingMaskLayer) {
     m_ancestorClippingMaskLayer->setOffsetFromLayoutObject(
         m_ancestorClippingLayer->offsetFromLayoutObject());
     m_ancestorClippingMaskLayer->setSize(m_ancestorClippingLayer->size());
     m_ancestorClippingMaskLayer->setNeedsDisplay();
   }
 
   // The primary layer is then parented in, and positioned relative to this
   // clipping layer.
-  graphicsLayerParentLocation = parentClipRect.location();
+  graphicsLayerParentLocation = snappedParentClipRect.location();
 }
 
 void CompositedLayerMapping::updateOverflowControlsHostLayerGeometry(
     const PaintLayer* compositingStackingContext,
     const PaintLayer* compositingContainer,
     IntPoint graphicsLayerParentLocation) {
   if (!m_overflowControlsHostLayer)
     return;
 
   // To position and clip the scrollbars correctly, m_overflowControlsHostLayer
@@ skipping 1679 matching lines @@
       containingSquashedLayer(clippingContainer, layers, layers.size());
   // Must be there, otherwise
   // CompositingLayerAssigner::canSquashIntoCurrentSquashingOwner would have
   // disallowed squashing.
   ASSERT(ancestorPaintInfo);
 
   // FIXME: this is a potential performance issue. We should consider caching
   // these clip rects or otherwise optimizing.
   ClipRectsContext clipRectsContext(ancestorPaintInfo->paintLayer,
                                     UncachedClipRects);
-  IntRect parentClipRect = pixelSnappedIntRect(
-      paintInfo.paintLayer->clipper(PaintLayer::DoNotUseGeometryMapper)
-          .backgroundClipRect(clipRectsContext)
-          .rect());
-  ASSERT(parentClipRect != LayoutRect::infiniteIntRect());
+  ClipRect parentClipRect;
+  paintInfo.paintLayer->clipper(PaintLayer::DoNotUseGeometryMapper)
+      .calculateBackgroundClipRect(clipRectsContext, parentClipRect);
+
+  IntRect snappedParentClipRect(pixelSnappedIntRect(parentClipRect.rect()));
+  DCHECK(snappedParentClipRect != LayoutRect::infiniteIntRect());
 
   // Convert from ancestor to local coordinates.
   IntSize ancestorToLocalOffset = paintInfo.offsetFromLayoutObject -
                                   ancestorPaintInfo->offsetFromLayoutObject;
-  parentClipRect.move(ancestorToLocalOffset);
-  return parentClipRect;
+  snappedParentClipRect.move(ancestorToLocalOffset);
+  return snappedParentClipRect;
 }
 
 void CompositedLayerMapping::doPaintTask(
     const GraphicsLayerPaintInfo& paintInfo,
     const GraphicsLayer& graphicsLayer,
     const PaintLayerFlags& paintLayerFlags,
     GraphicsContext& context,
     const IntRect& clip /* In the coords of rootLayer */) const {
   FontCachePurgePreventer fontCachePurgePreventer;
 
@@ skipping 588 matching lines @@
   } else if (graphicsLayer == m_decorationOutlineLayer.get()) {
     name = "Decoration Layer";
   } else {
     ASSERT_NOT_REACHED();
   }
 
   return name;
 }
 
 }  // namespace blink