Don't use cached subsequence when clip changes

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 "config.h"
 #include "core/paint/PaintLayerPainter.h"
 
 #include "core/frame/Settings.h"
 #include "core/layout/ClipPathOperation.h"
 #include "core/layout/LayoutBlock.h"
@@ skipping 203 matching lines @@
         return result;
 
     // TODO(skyostil): Unify this early-out logic with subsequence caching.
     if (m_paintLayer.layoutObject()->isLayoutPart() && toLayoutPart(m_paintLayer.layoutObject())->isThrottledFrameView())
         return FullyPainted;
 
     // Ensure our lists are up-to-date.
     m_paintLayer.stackingNode()->updateLayerListsIfNeeded();
 
     Optional<SubsequenceRecorder> subsequenceRecorder;
-    if (!paintingInfoArg.disableSubsequenceCache
-        && !context->printing()
+    if (!context->printing()
         && !(paintingInfoArg.globalPaintFlags() & GlobalPaintFlattenCompositingLayers)
         && !(paintFlags & (PaintLayerPaintingReflection | PaintLayerPaintingRootBackgroundOnly | PaintLayerPaintingOverlayScrollbars))
         && m_paintLayer.stackingNode()->isStackingContext()
         && PaintLayerStackingNodeIterator(*m_paintLayer.stackingNode(), AllChildren).next()) {
         if (!m_paintLayer.needsRepaint()
             && paintingInfoArg.scrollOffsetAccumulation == m_paintLayer.previousScrollOffsetAccumulationForPainting()
             && SubsequenceRecorder::useCachedSubsequenceIfPossible(*context, m_paintLayer))
             return result;
         subsequenceRecorder.emplace(*context, m_paintLayer);
     }
 
     PaintLayerPaintingInfo paintingInfo = paintingInfoArg;
 
-    // This is a workaround of ancestor clip change issue (crbug.com/533717).
-    // TODO(wangxianzhu):
-    // - spv1: This disables subsequence cache for all descendants of LayoutView with root-layer-scrolls because
-    //   LayoutView has overflow clip. Should find another workaround method working with root-layer-scrolls
-    //   if it ships before slimming paint v2. crbug.com/552030.
-    // - spv2: Ensure subsequence cache works with ancestor clip change. crbug.com/536138.
-    if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled() && m_paintLayer.layoutObject()->hasClipOrOverflowClip())
-        paintingInfo.disableSubsequenceCache = true;
-
     LayoutPoint offsetFromRoot;
     m_paintLayer.convertToLayerCoords(paintingInfo.rootLayer, offsetFromRoot);
 
     if (m_paintLayer.compositingState() == PaintsIntoOwnBacking)
         offsetFromRoot.move(m_paintLayer.subpixelAccumulation());
     else
         offsetFromRoot.move(paintingInfo.subPixelAccumulation);
 
     LayoutRect bounds = m_paintLayer.physicalBoundingBox(offsetFromRoot);
     if (!paintingInfo.paintDirtyRect.contains(bounds))
@@ skipping 450 matching lines @@
     if (!m_paintLayer.containsDirtyOverlayScrollbars())
         return;
 
     PaintLayerPaintingInfo paintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(damageRect)), paintFlags, LayoutSize(), paintingRoot);
     paintLayer(context, paintingInfo, PaintLayerPaintingOverlayScrollbars);
 
     m_paintLayer.setContainsDirtyOverlayScrollbars(false);
 }
 
 } // namespace blink