(WIP) Invalidation during painting (for synchronized painting)

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/ClipPathOperation.h"
 #include "core/layout/LayoutBlock.h"
@@ skipping 507 matching lines @@
     LayoutSize adjustedSubPixelAccumulation = paintingInfo.subPixelAccumulation + (delta - roundedDelta);
 
     // TODO(jbroman): Put the real transform origin here, instead of using a
     // matrix with the origin baked in.
     FloatPoint3D transformOrigin;
     Transform3DRecorder transform3DRecorder(context, *m_paintLayer.layoutObject(), DisplayItem::Transform3DElementTransform, transform, transformOrigin);
 
     // Now do a paint with the root layer shifted to be us.
     PaintLayerPaintingInfo transformedPaintingInfo(&m_paintLayer, LayoutRect(enclosingIntRect(transform.inverse().mapRect(paintingInfo.paintDirtyRect))), paintingInfo.globalPaintFlags(),
         adjustedSubPixelAccumulation);
+    if (paintingInfo.ancestorHasNonIdentityAndNonTranslateTransform || !transform.isIdentityOrTranslation())
+        transformedPaintingInfo.ancestorHasNonIdentityAndNonTranslateTransform = true;
     transformedPaintingInfo.ancestorHasClipPathClipping = paintingInfo.ancestorHasClipPathClipping;
     return paintLayerContentsAndReflection(context, transformedPaintingInfo, paintFlags, ForceSingleFragment);
 }
 
 PaintLayerPainter::PaintResult PaintLayerPainter::paintChildren(unsigned childrenToVisit, GraphicsContext& context, const PaintLayerPaintingInfo& paintingInfo, PaintLayerFlags paintFlags)
 {
     PaintResult result = FullyPainted;
     if (!m_paintLayer.hasSelfPaintingLayerDescendant())
         return result;
 
@@ skipping 119 matching lines @@
             // for this layer seperately, with the scroll offset accumulated from the root layer to the parent of this
             // layer, to get the same result as ScrollRecorder in BlockPainter.
             paintOffset += paintingInfo.scrollOffsetAccumulation;
 
             newCullRect.move(paintingInfo.scrollOffsetAccumulation);
             scrollRecorder.emplace(context, *m_paintLayer.layoutObject(), phase, paintingInfo.scrollOffsetAccumulation);
         }
     }
     PaintInfo paintInfo(context, pixelSnappedIntRect(newCullRect), phase,
         paintingInfo.globalPaintFlags(), paintFlags, paintingInfo.rootLayer->layoutObject());
+    Optional<PaintInvalidationState> paintInvalidationState;
+    if (RuntimeEnabledFeatures::slimmingPaintSynchronizedPaintingEnabled()) {
+        unsigned flags = 0;
+        if (clipState == HasClipped || paintingInfo.clipToDirtyRect)
+            flags |= PaintInvalidationState::HasClip;
+        if (paintingInfo.ancestorHasNonIdentityAndNonTranslateTransform)
+            flags |= PaintInvalidationState::HasNonIdentityAndNonTranslateTransform;
+        paintInvalidationState.emplace(*paintingInfo.rootLayer->layoutObject(), clipRect.rect(), flags);
+        paintInfo.paintInvalidationState = &*paintInvalidationState;
+    }
 
     m_paintLayer.layoutObject()->paint(paintInfo, paintOffset);
 }
 
 void PaintLayerPainter::paintBackgroundForFragments(const PaintLayerFragments& layerFragments,
     GraphicsContext& context, const LayoutRect& transparencyPaintDirtyRect,
     const PaintLayerPaintingInfo& localPaintingInfo, PaintLayerFlags paintFlags)
 {
     bool needsScope = layerFragments.size() > 1;
     for (auto& fragment : layerFragments) {
@@ skipping 90 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