Move PreviousBoxGeometries from BoxPaintInvalidator into LayoutBox::m_rareData

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

 // Copyright 2016 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/BoxPaintInvalidator.h"
 
 #include "core/frame/Settings.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/compositing/CompositedLayerMapping.h"
 #include "core/paint/ObjectPaintInvalidator.h"
 #include "core/paint/PaintInvalidator.h"
 #include "core/paint/PaintLayer.h"
 #include "core/paint/PaintLayerScrollableArea.h"
 #include "platform/geometry/LayoutRect.h"
 
 namespace blink {
 
-struct PreviousBoxGeometries {
-  LayoutRect contentBoxRect;
-  LayoutRect layoutOverflowRect;
-};
-
-typedef HashMap<const LayoutBox*, PreviousBoxGeometries>
-    PreviousBoxGeometriesMap;
-static PreviousBoxGeometriesMap& previousBoxGeometriesMap() {
-  DEFINE_STATIC_LOCAL(PreviousBoxGeometriesMap, map, ());
-  return map;
-}
-
-void BoxPaintInvalidator::boxWillBeDestroyed(const LayoutBox& box) {
-  DCHECK(box.hasPreviousBoxGeometries() ==
-         previousBoxGeometriesMap().contains(&box));
-  if (box.hasPreviousBoxGeometries())
-    previousBoxGeometriesMap().erase(&box);
-}
-
 static LayoutRect computeRightDelta(const LayoutPoint& location,
                                     const LayoutSize& oldSize,
                                     const LayoutSize& newSize,
                                     const LayoutUnit& extraWidth) {
   LayoutUnit delta = newSize.width() - oldSize.width();
   if (delta > 0) {
     return LayoutRect(location.x() + oldSize.width() - extraWidth, location.y(),
                       delta + extraWidth, newSize.height());
   }
   if (delta < 0) {
@@ skipping 64 matching lines @@
     // can safely exit here.
     if (layoutView.usesCompositing() &&
         !RuntimeEnabledFeatures::rootLayerScrollingEnabled())
       return reason;
   }
 
   const ComputedStyle& style = m_box.styleRef();
 
   if ((style.backgroundLayers().thisOrNextLayersUseContentBox() ||
        style.maskLayers().thisOrNextLayersUseContentBox()) &&
-      previousContentBoxRect() != m_box.contentBoxRect())
+      m_box.previousContentBoxSize() != m_box.contentBoxRect().size())
     return PaintInvalidationContentBoxChange;
 
   LayoutSize oldBorderBoxSize = m_box.previousSize();
   LayoutSize newBorderBoxSize = m_box.size();
   bool borderBoxChanged = oldBorderBoxSize != newBorderBoxSize;
   if (!borderBoxChanged && m_context.oldVisualRect == m_context.newVisualRect)
     return PaintInvalidationNone;
 
   // If either border box changed or bounds changed, and old or new border box
   // doesn't equal old or new bounds, incremental invalidation is not
@@ skipping 78 matching lines @@
   return false;
 }
 
 void BoxPaintInvalidator::invalidateScrollingContentsBackgroundIfNeeded() {
   bool paintsOntoScrollingContentsLayer =
       backgroundPaintsOntoScrollingContentsLayer();
   if (!paintsOntoScrollingContentsLayer &&
       !backgroundGeometryDependsOnLayoutOverflowRect())
     return;
 
-  const LayoutRect& oldLayoutOverflow = previousLayoutOverflowRect();
+  const LayoutRect& oldLayoutOverflow = m_box.previousLayoutOverflowRect();
   LayoutRect newLayoutOverflow = m_box.layoutOverflowRect();
 
   bool shouldFullyInvalidateOnScrollingContentsLayer = false;
   if (m_box.backgroundChangedSinceLastPaintInvalidation()) {
     if (!paintsOntoScrollingContentsLayer) {
       // The box should have been set needing full invalidation on style change.
       DCHECK(m_box.shouldDoFullPaintInvalidation());
       return;
     }
     shouldFullyInvalidateOnScrollingContentsLayer = true;
@@ skipping 69 matching lines @@
 
   if (PaintLayerScrollableArea* area = m_box.getScrollableArea())
     area->invalidatePaintOfScrollControlsIfNeeded(m_context);
 
   // This is for the next invalidatePaintIfNeeded so must be at the end.
   savePreviousBoxGeometriesIfNeeded();
 
   return reason;
 }
 
-bool BoxPaintInvalidator::needsToSavePreviousBoxGeometries() {
+bool BoxPaintInvalidator::
+    needsToSavePreviousContentBoxSizeOrLayoutOverflowRect() {
   // Don't save old box geometries if the paint rect is empty because we'll
   // fully invalidate once the paint rect becomes non-empty.
   if (m_context.newVisualRect.isEmpty())
     return false;
 
   if (m_box.paintedOutputOfObjectHasNoEffectRegardlessOfSize())
     return false;
 
   const ComputedStyle& style = m_box.styleRef();
 
   // Background and mask layers can depend on other boxes than border box. See
   // crbug.com/490533
-  if (style.backgroundLayers().thisOrNextLayersUseContentBox() ||
-      style.maskLayers().thisOrNextLayersUseContentBox() ||
-      backgroundGeometryDependsOnLayoutOverflowRect() ||
-      backgroundPaintsOntoScrollingContentsLayer())
+  if ((style.backgroundLayers().thisOrNextLayersUseContentBox() ||
+       style.maskLayers().thisOrNextLayersUseContentBox()) &&
+      m_box.contentBoxRect().size() != m_box.size())
+    return true;
+  if ((backgroundGeometryDependsOnLayoutOverflowRect() ||
+       backgroundPaintsOntoScrollingContentsLayer()) &&
+      m_box.layoutOverflowRect() != m_box.borderBoxRect())
     return true;
 
   return false;
 }
 
 void BoxPaintInvalidator::savePreviousBoxGeometriesIfNeeded() {
-  m_box.getMutableForPainting().setPreviousSize(m_box.size());
+  m_box.getMutableForPainting().savePreviousSize();
 
-  DCHECK(m_box.hasPreviousBoxGeometries() ==
-         previousBoxGeometriesMap().contains(&m_box));
-  if (!needsToSavePreviousBoxGeometries()) {
-    if (m_box.hasPreviousBoxGeometries()) {
-      previousBoxGeometriesMap().erase(&m_box);
-      m_box.getMutableForPainting().setHasPreviousBoxGeometries(false);
-    }
-    return;
+  if (needsToSavePreviousContentBoxSizeOrLayoutOverflowRect()) {
+    m_box.getMutableForPainting()
+        .savePreviousContentBoxSizeAndLayoutOverflowRect();
+  } else {
+    m_box.getMutableForPainting()
+        .clearPreviousContentBoxSizeAndLayoutOverflowRect();
   }
-
-  PreviousBoxGeometries geometries = {m_box.contentBoxRect(),
-                                      m_box.layoutOverflowRect()};
-  previousBoxGeometriesMap().set(&m_box, geometries);
-  m_box.getMutableForPainting().setHasPreviousBoxGeometries(true);
-}
-
-LayoutRect BoxPaintInvalidator::previousContentBoxRect() {
-  DCHECK(m_box.hasPreviousBoxGeometries() ==
-         previousBoxGeometriesMap().contains(&m_box));
-  return m_box.hasPreviousBoxGeometries()
-             ? previousBoxGeometriesMap().get(&m_box).contentBoxRect
-             : LayoutRect(LayoutPoint(), m_box.previousSize());
-}
-
-LayoutRect BoxPaintInvalidator::previousLayoutOverflowRect() {
-  DCHECK(m_box.hasPreviousBoxGeometries() ==
-         previousBoxGeometriesMap().contains(&m_box));
-  return m_box.hasPreviousBoxGeometries()
-             ? previousBoxGeometriesMap().get(&m_box).layoutOverflowRect
-             : LayoutRect(LayoutPoint(), m_box.previousSize());
 }
 
 }  // namespace blink