Skip paint property update and visual rect update if no geometry change

third_party/WebKit/Source/core/paint/PaintInvalidator.h

 // 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.
 
 #ifndef PaintInvalidator_h
 #define PaintInvalidator_h
 
+#include "core/layout/LayoutObject.h"
+#include "core/paint/PaintPropertyTreeBuilder.h"
 #include "platform/geometry/LayoutRect.h"
 #include "platform/graphics/paint/GeometryMapper.h"
 #include "wtf/Vector.h"
 
 namespace blink {
 
-class FrameView;
-class LayoutBoxModelObject;
-class LayoutObject;
-class PaintLayer;
-struct PaintPropertyTreeBuilderContext;
-
 struct PaintInvalidatorContext {
   PaintInvalidatorContext(
-      const PaintPropertyTreeBuilderContext& treeBuilderContext,
+      const PaintPropertyTreeBuilderContext* treeBuilderContext,
       GeometryMapper& geometryMapper)
       : parentContext(nullptr),
         m_treeBuilderContext(treeBuilderContext),
         m_geometryMapper(geometryMapper) {}
 
   PaintInvalidatorContext(
-      const PaintPropertyTreeBuilderContext& treeBuilderContext,
+      const PaintPropertyTreeBuilderContext* treeBuilderContext,
       const PaintInvalidatorContext& parentContext)
       : parentContext(&parentContext),
         forcedSubtreeInvalidationFlags(
             parentContext.forcedSubtreeInvalidationFlags),
         paintInvalidationContainer(parentContext.paintInvalidationContainer),
         paintInvalidationContainerForStackedContents(
             parentContext.paintInvalidationContainerForStackedContents),
         paintingLayer(parentContext.paintingLayer),
         m_treeBuilderContext(treeBuilderContext),
         m_geometryMapper(parentContext.m_geometryMapper) {}
 
   // This method is virtual temporarily to adapt PaintInvalidatorContext and the
   // legacy PaintInvalidationState for code shared by old code and new code.
   virtual void mapLocalRectToVisualRectInBacking(const LayoutObject&,
                                                  LayoutRect&) const;
 
+  bool needsVisualRectUpdate(const LayoutObject& object) const {
+    if (!RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
+      return true;
+#if DCHECK_IS_ON()
+    if (m_forceVisualRectUpdateForChecking)
+      return true;
+#endif
+    return object.needsPaintOffsetAndVisualRectUpdate() ||
+           (forcedSubtreeInvalidationFlags &
+            PaintInvalidatorContext::ForcedSubtreeVisualRectUpdate);
+  }
+
   const PaintInvalidatorContext* parentContext;
 
   enum ForcedSubtreeInvalidationFlag {
     ForcedSubtreeInvalidationChecking = 1 << 0,
-    ForcedSubtreeInvalidationRectUpdate = 1 << 1,
+    ForcedSubtreeVisualRectUpdate = 1 << 1,
     ForcedSubtreeFullInvalidation = 1 << 2,
     ForcedSubtreeFullInvalidationForStackedContents = 1 << 3,
     ForcedSubtreeSVGResourceChange = 1 << 4,
+
     // TODO(crbug.com/637313): This is temporary before we support filters in
     // paint property tree.
     ForcedSubtreeSlowPathRect = 1 << 5,
 
     // The paint invalidation tree walk invalidates paint caches, such as
     // DisplayItemClients and subsequence caches, and also the regions
     // into which objects raster pixels. When this flag is set, raster region
     // invalidations are not issued.
     //
     // Context: some objects in this paint walk, for example SVG resource
@@ skipping 30 matching lines @@
   // Store the origin of the object's local coordinates in the paint
   // invalidation backing's coordinates. They are used to detect layoutObject
   // shifts that force a full invalidation and invalidation check in subtree.
   // The points do *not* account for composited scrolling. See
   // LayoutObject::adjustVisualRectForCompositedScrolling().
   LayoutPoint oldLocation;
   LayoutPoint newLocation;
 
  private:
   friend class PaintInvalidator;
-  const PaintPropertyTreeBuilderContext& m_treeBuilderContext;
+  const PaintPropertyTreeBuilderContext* m_treeBuilderContext;
   GeometryMapper& m_geometryMapper;
+
+#if DCHECK_IS_ON()
+  friend class FindVisualRectNeedingUpdateScopeBase;
+  mutable bool m_forceVisualRectUpdateForChecking = false;
+#endif
 };
 
 class PaintInvalidator {
  public:
   void invalidatePaintIfNeeded(FrameView&, PaintInvalidatorContext&);
   void invalidatePaintIfNeeded(const LayoutObject&, PaintInvalidatorContext&);
 
   // Process objects needing paint invalidation on the next frame.
   // See the definition of PaintInvalidationDelayedFull for more details.
   void processPendingDelayedPaintInvalidations();
 
  private:
   friend struct PaintInvalidatorContext;
   template <typename Rect, typename Point>
   static LayoutRect mapLocalRectToVisualRectInBacking(
       const LayoutObject&,
       const Rect&,
       const PaintInvalidatorContext&);
 
   ALWAYS_INLINE LayoutRect
   computeVisualRectInBacking(const LayoutObject&,
                              const PaintInvalidatorContext&);
   ALWAYS_INLINE LayoutPoint
   computeLocationInBacking(const LayoutObject&, const PaintInvalidatorContext&);
   ALWAYS_INLINE void updatePaintingLayer(const LayoutObject&,
                                          PaintInvalidatorContext&);
   ALWAYS_INLINE void updatePaintInvalidationContainer(const LayoutObject&,
                                                       PaintInvalidatorContext&);
+  ALWAYS_INLINE void updateVisualRectIfNeeded(const LayoutObject&,
+                                              PaintInvalidatorContext&);
   ALWAYS_INLINE void updateVisualRect(const LayoutObject&,
                                       PaintInvalidatorContext&);
 
   Vector<const LayoutObject*> m_pendingDelayedPaintInvalidations;
 };
 
 }  // namespace blink
 
 #endif  // PaintInvalidator_h