Split-out change for https://codereview.chromium.org/1145993002/ patch set 11

Source/core/layout/LayoutView.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 201 matching lines @@
 void LayoutView::layout()
 {
     if (!document().paginated())
         setPageLogicalHeight(0);
 
     if (shouldUsePrintingLayout())
         m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = logicalWidth();
 
     SubtreeLayoutScope layoutScope(*this);
 
-    LayoutRect oldLayoutOverflowRect = layoutOverflowRect();
-
     // Use calcWidth/Height to get the new width/height, since this will take the full page zoom factor into account.
     bool relayoutChildren = !shouldUsePrintingLayout() && (!m_frameView
         || logicalWidth() != viewLogicalWidthForBoxSizing()
         || logicalHeight() != viewLogicalHeightForBoxSizing());
     if (relayoutChildren) {
         layoutScope.setChildNeedsLayout(this);
         for (LayoutObject* child = firstChild(); child; child = child->nextSibling()) {
             if (child->isSVGRoot())
                 continue;
 
@@ skipping 11 matching lines @@
     ASSERT(!m_layoutState);
     if (!needsLayout())
         return;
 
     LayoutState rootLayoutState(pageLogicalHeight(), pageLogicalHeightChanged(), *this);
 
     m_pageLogicalHeightChanged = false;
 
     layoutContent();
 
-    if (RuntimeEnabledFeatures::slimmingPaintEnabled() && layoutOverflowRect() != oldLayoutOverflowRect) {
-        // The document element paints the viewport background, so we need to invalidate it when
-        // layout overflow changes.
-        // FIXME: Improve viewport background styling/invalidation/painting. crbug.com/475115
-        if (Element* documentElement = document().documentElement()) {
-            if (LayoutObject* rootObject = documentElement->layoutObject())
-                rootObject->setShouldDoFullPaintInvalidation();
-        }
-    }
-
 #if ENABLE(ASSERT)
     checkLayoutState();
 #endif
     clearNeedsLayout();
 }
 
+void LayoutView::styleDidChange(StyleDifference diff, const ComputedStyle* oldStyle)
+{
+    const ComputedStyle& newStyle = styleRef();
+
+    if (oldStyle && oldStyle->hasEntirelyFixedBackground() != newStyle.hasEntirelyFixedBackground())
+        compositor()->setNeedsUpdateFixedBackground();
+
+    LayoutBlockFlow::styleDidChange(diff, oldStyle);
+}
+
+PaintInvalidationReason LayoutView::invalidatePaintIfNeeded(PaintInvalidationState& paintInvalidationState, const LayoutBoxModelObject& newPaintInvalidationContainer)
+{
+    const LayoutObject* rootObject = document().documentElement() ? document().documentElement()->layoutObject() : nullptr;
+    TransformationMatrix newTransform;
+    LayoutSize newBorderBoxSize;
+    LayoutRect newPaddingBoxRect;
+    LayoutRect newContentBoxRect;
+
+    if (rootObject && rootObject->isBox()) {
+        const LayoutBox& rootBox = toLayoutBox(*rootObject);
+        if (rootBox.hasLayer()) {
+            const DeprecatedPaintLayer& rootLayer = *rootBox.layer();
+            LayoutPoint offset;
+            rootLayer.convertToLayerCoords(nullptr, offset);
+            newTransform.translate(offset.x(), offset.y());
+            newTransform.multiply(rootLayer.currentTransform());
+        }
+        newBorderBoxSize = rootBox.size();
+        newPaddingBoxRect = rootBox.paddingBoxRect();
+        newContentBoxRect = rootBox.contentBoxRect();
+    }
+
+    if (m_previousRootBackgroundPositioning.transform != newTransform)
+        setShouldDoFullPaintInvalidation(PaintInvalidationLocationChange);
+
+    const FillLayer& backgroundLayers = style()->backgroundLayers();
+    if (mustInvalidateFillLayersPaintOnWidthChange(backgroundLayers) || mustInvalidateFillLayersPaintOnHeightChange(backgroundLayers)) {
+        if (m_previousRootBackgroundPositioning.borderBoxSize != newBorderBoxSize
+            || m_previousRootBackgroundPositioning.paddingBoxRect != newPaddingBoxRect
+            || m_previousRootBackgroundPositioning.contentBoxRect != newContentBoxRect) {
+            setShouldDoFullPaintInvalidation(PaintInvalidationBorderBoxChange);
+        }
+    }
+
+    m_previousRootBackgroundPositioning.transform = newTransform;
+    m_previousRootBackgroundPositioning.borderBoxSize = newBorderBoxSize;
+    m_previousRootBackgroundPositioning.paddingBoxRect = newPaddingBoxRect;
+    m_previousRootBackgroundPositioning.contentBoxRect = newContentBoxRect;
+
+    return LayoutBox::invalidatePaintIfNeeded(paintInvalidationState, newPaintInvalidationContainer);
+}
+
 void LayoutView::mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed, const PaintInvalidationState* paintInvalidationState) const
 {
     ASSERT_UNUSED(wasFixed, !wasFixed || *wasFixed == static_cast<bool>(mode & IsFixed));
 
     if (!paintInvalidationContainer && mode & UseTransforms && shouldUseTransformFromContainer(0)) {
         TransformationMatrix t;
         getTransformFromContainer(0, LayoutSize(), t);
         transformState.applyTransform(t);
     }
 
@@ skipping 680 matching lines @@
     return viewHeight(IncludeScrollbars) / scale;
 }
 
 void LayoutView::willBeDestroyed()
 {
     LayoutBlockFlow::willBeDestroyed();
     m_compositor.clear();
 }
 
 } // namespace blink