SPv2: Use GeometryMapper to implement PaintLayerClipper.

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

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/PaintLayerPainter.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutView.h"
@@ skipping 217 matching lines @@
 
 static bool shouldRepaintSubsequence(PaintLayer& paintLayer, const PaintLayerPaintingInfo& paintingInfo, ShouldRespectOverflowClipType respectOverflowClip, const LayoutSize& subpixelAccumulation)
 {
     bool needsRepaint = false;
 
     // Repaint subsequence if the layer is marked for needing repaint.
     if (paintLayer.needsRepaint())
         needsRepaint = true;
 
     // Repaint if layer's clip changes.
-    ClipRects& clipRects = paintLayer.clipper().paintingClipRects(paintingInfo.rootLayer, respectOverflowClip, subpixelAccumulation);
-    ClipRects* previousClipRects = paintLayer.previousPaintingClipRects();
-    if (!needsRepaint && &clipRects != previousClipRects && (!previousClipRects || clipRects != *previousClipRects))
-        needsRepaint = true;
-    paintLayer.setPreviousPaintingClipRects(clipRects);
+    if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+        ClipRects& clipRects = paintLayer.clipper().paintingClipRects(paintingInfo.rootLayer, respectOverflowClip, subpixelAccumulation);
+        ClipRects* previousClipRects = paintLayer.previousPaintingClipRects();
+        if (!needsRepaint && &clipRects != previousClipRects && (!previousClipRects || clipRects != *previousClipRects))
+            needsRepaint = true;
+        paintLayer.setPreviousPaintingClipRects(clipRects);
+    }
 
     // Repaint if previously the layer might be clipped by paintDirtyRect and paintDirtyRect changes.
     if (!needsRepaint && paintLayer.previousPaintResult() == PaintLayerPainter::MayBeClippedByPaintDirtyRect && paintLayer.previousPaintDirtyRect() != paintingInfo.paintDirtyRect)
         needsRepaint = true;
     paintLayer.setPreviousPaintDirtyRect(paintingInfo.paintDirtyRect);
 
     // Repaint if scroll offset accumulation changes.
     if (!needsRepaint && paintingInfo.scrollOffsetAccumulation != paintLayer.previousScrollOffsetAccumulationForPainting())
         needsRepaint = true;
     paintLayer.setPreviousScrollOffsetAccumulationForPainting(paintingInfo.scrollOffsetAccumulation);
@@ skipping 85 matching lines @@
     if (shouldPaintContent || shouldPaintSelfOutline || isPaintingOverlayScrollbars) {
         // Collect the fragments. This will compute the clip rectangles and paint offsets for each layer fragment.
         ClipRectsCacheSlot cacheSlot = (paintFlags & PaintLayerUncachedClipRects) ? UncachedClipRects : PaintingClipRects;
         // TODO(trchen): We haven't decided how to handle visual fragmentation with SPv2.
         // Related thread https://groups.google.com/a/chromium.org/forum/#!topic/graphics-dev/81XuWFf-mxM
         if (fragmentPolicy == ForceSingleFragment || RuntimeEnabledFeatures::slimmingPaintV2Enabled())
             m_paintLayer.appendSingleFragmentIgnoringPagination(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.paintDirtyRect, cacheSlot, IgnoreOverlayScrollbarSize, respectOverflowClip, &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
         else
             m_paintLayer.collectFragments(layerFragments, localPaintingInfo.rootLayer, localPaintingInfo.paintDirtyRect, cacheSlot, IgnoreOverlayScrollbarSize, respectOverflowClip, &offsetFromRoot, localPaintingInfo.subPixelAccumulation);
 
-        // TODO(trchen): Needs to adjust cull rect between transform spaces. https://crbug.com/593596
-        // Disables layer culling for SPv2 for now because the space of the cull rect doesn't match
-        // the space we paint in. Clipping will still be done by clip nodes, so this won't cause
-        // rendering issues, only performance.
-        if (RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
-            layerFragments[0].backgroundRect = LayoutRect(LayoutRect::infiniteIntRect());
-            layerFragments[0].foregroundRect = LayoutRect(LayoutRect::infiniteIntRect());
-        }
-
         if (shouldPaintContent) {
             // TODO(wangxianzhu): This is for old slow scrolling. Implement similar optimization for slimming paint v2.
             shouldPaintContent = atLeastOneFragmentIntersectsDamageRect(layerFragments, localPaintingInfo, paintFlags, offsetFromRoot);
             if (!shouldPaintContent)
                 result = MayBeClippedByPaintDirtyRect;
         }
     }
 
     bool selectionOnly = localPaintingInfo.getGlobalPaintFlags() & GlobalPaintSelectionOnly;
 
@@ skipping 449 matching lines @@
     if (!m_paintLayer.containsDirtyOverlayScrollbars())
         return;
 
     PaintLayerPaintingInfo paintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(damageRect)), paintFlags, LayoutSize());
     paintLayer(context, paintingInfo, PaintLayerPaintingOverlayScrollbars);
 
     m_paintLayer.setContainsDirtyOverlayScrollbars(false);
 }
 
 } // namespace blink