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

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

Index: third_party/WebKit/Source/core/paint/PaintInvalidator.h
diff --git a/third_party/WebKit/Source/core/paint/PaintInvalidator.h b/third_party/WebKit/Source/core/paint/PaintInvalidator.h
index 37e609a2abd27fb80c88f674a7313668d31b4d0d..b396ee793cd5619b1f07cef3b95adafdf0645802 100644
--- a/third_party/WebKit/Source/core/paint/PaintInvalidator.h
+++ b/third_party/WebKit/Source/core/paint/PaintInvalidator.h
@@ -5,28 +5,24 @@
 #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(
@@ -43,14 +39,27 @@ struct PaintInvalidatorContext {
   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,
@@ -101,8 +110,13 @@ struct PaintInvalidatorContext {
 
  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 {
@@ -131,6 +145,8 @@ class PaintInvalidator {
                                          PaintInvalidatorContext&);
   ALWAYS_INLINE void updatePaintInvalidationContainer(const LayoutObject&,
                                                       PaintInvalidatorContext&);
+  ALWAYS_INLINE void updateVisualRectIfNeeded(const LayoutObject&,
+                                              PaintInvalidatorContext&);
   ALWAYS_INLINE void updateVisualRect(const LayoutObject&,
                                       PaintInvalidatorContext&);