Let synchronized painting generate correct paint invalidation rects

third_party/WebKit/Source/core/layout/LayoutBox.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2005 Allan Sandfeld Jensen (kde@carewolf.com)
  *           (C) 2005, 2006 Samuel Weinig (sam.weinig@gmail.com)
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. 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
@@ skipping 1409 matching lines @@
     if (fullInvalidationReason == PaintInvalidationDelayedFull) {
         if (!intersectsVisibleViewport())
             return PaintInvalidationDelayedFull;
 
         // Reset state back to regular full paint invalidation if the object is onscreen.
         setShouldDoFullPaintInvalidation(PaintInvalidationFull);
     }
 
     PaintInvalidationReason reason = LayoutBoxModelObject::invalidatePaintIfNeeded(paintInvalidationState, newPaintInvalidationContainer);
 
-    // If we are set to do a full paint invalidation that means the LayoutView will be
-    // issue paint invalidations. We can then skip issuing of paint invalidations for the child
-    // layoutObjects as they'll be covered by the LayoutView.
-    if (!view()->doingFullPaintInvalidation() && !isFullPaintInvalidationReason(reason)) {
+    bool willDoFullInvalidation = view()->doingFullPaintInvalidation() || isFullPaintInvalidationReason(reason);
+    if (!willDoFullInvalidation)
         invalidatePaintForOverflowIfNeeded();
 
-        // Issue paint invalidations for any scrollbars if there is a scrollable area for this layoutObject.
-        if (ScrollableArea* area = scrollableArea()) {
-            // In slimming paint mode, we already invalidated the display item clients of the scrollbars
-            // during PaintLayerScrollableArea::invalidateScrollbarRect(). However, for now we still need to
-            // invalidate the rectangles to trigger repaints.
-            if (area->hasVerticalBarDamage())
+    // Issue paint invalidations for any scrollbars if there is a scrollable area for this layoutObject.
+    if (ScrollableArea* area = scrollableArea()) {
+        if (area->hasVerticalBarDamage()) {
+            if (!willDoFullInvalidation)
                 invalidatePaintRectangleNotInvalidatingDisplayItemClients(LayoutRect(area->verticalBarDamage()));
-            if (area->hasHorizontalBarDamage())
+            // TODO(wangxianzhu): Pass current bounds of the scrollbar to PaintController. crbug.com/547119.
+            if (Scrollbar* verticalScrollbar = area->verticalScrollbar())
+                invalidateDisplayItemClient(*verticalScrollbar);
+        }
+        if (area->hasHorizontalBarDamage()) {
+            if (!willDoFullInvalidation)
                 invalidatePaintRectangleNotInvalidatingDisplayItemClients(LayoutRect(area->horizontalBarDamage()));
+            // TODO(wangxianzhu): Pass current bounds of the scrollbar to PaintController. crbug.com/547119.
+            if (Scrollbar* horizontalScrollbar = area->horizontalScrollbar())
+                invalidateDisplayItemClient(*horizontalScrollbar);
         }
     }
 
     // This is for the next invalidatePaintIfNeeded so must be at the end.
     savePreviousBoxSizesIfNeeded();
     return reason;
 }
 
 void LayoutBox::clearPaintInvalidationState(const PaintInvalidationState& paintInvalidationState)
 {
@@ skipping 3381 matching lines @@
     StyleImage* borderImage = style()->borderImage().image();
     return borderImage && borderImage->canRender(*this, style()->effectiveZoom()) && borderImage->isLoaded();
 }
 
 ShapeOutsideInfo* LayoutBox::shapeOutsideInfo() const
 {
     return ShapeOutsideInfo::isEnabledFor(*this) ? ShapeOutsideInfo::info(*this) : nullptr;
 }
 
 } // namespace blink