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

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

Index: third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
index 3d9ec1d68025a2fb48b1b0e85c04b0e980f71e88..b56c6845d6c8d3fca7b1243e90779ad9abeb86fb 100644
--- a/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
@@ -11,6 +11,7 @@
 #include "core/layout/LayoutScrollbar.h"
 #include "core/layout/LayoutScrollbarPart.h"
 #include "core/layout/PaintInvalidationState.h"
+#include "core/paint/FindPaintOffsetAndVisualRectNeedingUpdate.h"
 #include "core/paint/ObjectPaintInvalidator.h"
 #include "core/paint/PaintInvalidator.h"
 #include "core/paint/PaintLayer.h"
@@ -34,8 +35,16 @@ void PaintInvalidationCapableScrollableArea::willRemoveScrollbar(
 static LayoutRect scrollControlVisualRect(
     const IntRect& scrollControlRect,
     const LayoutBox& box,
-    const PaintInvalidatorContext& context) {
+    const PaintInvalidatorContext& context,
+    const LayoutRect& previousVisualRect) {
   LayoutRect visualRect(scrollControlRect);
+#if DCHECK_IS_ON()
+  FindVisualRectNeedingUpdateScope finder(box, context, previousVisualRect,
+                                          visualRect);
+#endif
+  if (!context.needsVisualRectUpdate(box))
+    return previousVisualRect;
+
   // No need to apply any paint offset. Scroll controls paint in a different
   // transform space than their contained box (the scrollbarPaintOffset
   // transform node).
@@ -82,12 +91,12 @@ static LayoutRect invalidatePaintOfScrollbarIfNeeded(
     const PaintInvalidatorContext& context) {
   bool isOverlay = scrollbar && scrollbar->isOverlayScrollbar();
 
+  LayoutRect newVisualRect;
   // Calculate visual rect of the scrollbar, except overlay composited
   // scrollbars because we invalidate the graphics layer only.
-  LayoutRect newVisualRect;
   if (scrollbar && !(graphicsLayer && isOverlay)) {
-    newVisualRect =
-        scrollControlVisualRect(scrollbar->frameRect(), box, context);
+    newVisualRect = scrollControlVisualRect(scrollbar->frameRect(), box,
+                                            context, previousVisualRect);
   }
 
   bool needsPaintInvalidation = needsPaintInvalidationArg;
@@ -160,7 +169,8 @@ void PaintInvalidationCapableScrollableArea::
       verticalScrollbarNeedsPaintInvalidation(), box, context));
 
   LayoutRect scrollCornerAndResizerVisualRect =
-      scrollControlVisualRect(scrollCornerAndResizerRect(), box, context);
+      scrollControlVisualRect(scrollCornerAndResizerRect(), box, context,
+                              m_scrollCornerAndResizerVisualRect);
   const LayoutBoxModelObject& paintInvalidationContainer =
       *context.paintInvalidationContainer;
   if (invalidatePaintOfScrollControlIfNeeded(