[SPInvalidation] Invalidate all paint and properties for printing

third_party/WebKit/Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights
    reserved.
 
    This library is free software; you can redistribute it and/or
@@ skipping 730 matching lines @@
   // tree as needing a paint property update.
   void setOnlyThisNeedsPaintPropertyUpdateForTesting() {
     m_needsPaintPropertyUpdate = true;
   }
 #endif
   void clearNeedsPaintPropertyUpdate() {
     DCHECK_EQ(lifecycle().state(), DocumentLifecycle::InPrePaint);
     m_needsPaintPropertyUpdate = false;
   }
   bool needsPaintPropertyUpdate() const { return m_needsPaintPropertyUpdate; }
+
+  // Set when the whole frame subtree needs full paint invalidation and paint

[pdr., 2016/12/15 06:07:24]

Why is a full paint property tree rebuild necessary, beyond the rebuilding that
occurs when printing causes a layout?

[Xianzhu, 2016/12/15 16:59:11]

There would be many under-invalidations in paint and paint properties just based
on layout. We are also doing the similar thing in spv1 with a heavier hammer:
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/core/frame/Loc....

This change replaces the whole tree walk setting shouldDoFullPaintInvalidation
on every object with a flag, and let it also work for paint property
invalidation.

It would be great if we knew exactly why the forced layouts before and after
printing don't cause enough paint invalidations without the forced paint
invalidation.

[Xianzhu, 2016/12/15 17:05:42]

The whole tree walk for SPv1 is in
LayoutView::setShouldDoFullPaintInvalidationForViewAndAllDescendants().

+  // property update, e.g. when beginning or finishing printing.
+  void setShouldInvalidateAllPaintAndPaintProperties() {
+    m_shouldInvalidateAllPaintAndPaintProperties = true;
+  }
+  void clearShouldInvalidateAllPaintAndPaintProperties() {
+    m_shouldInvalidateAllPaintAndPaintProperties = true;
+  }
+  bool shouldInvalidateAllPaintAndPaintProperties() const {
+    return m_shouldInvalidateAllPaintAndPaintProperties;
+  }
+
   // TODO(ojan): Merge this with IntersectionObserver once it lands.
   IntRect computeVisibleArea();
 
   // Viewport size that should be used for viewport units (i.e. 'vh'/'vw').
   FloatSize viewportSizeForViewportUnits() const;
 
   ScrollAnchor* scrollAnchor() override { return &m_scrollAnchor; }
   void clearScrollAnchor();
   bool shouldPerformScrollAnchoring() const override;
   void enqueueScrollAnchoringAdjustment(ScrollableArea*);
@@ skipping 335 matching lines @@
   // TODO(trchen): This will not be needed once settings->rootLayerScrolls() is
   // enabled.
   RefPtr<ClipPaintPropertyNode> m_contentClip;
   // The property tree state that should be used for painting contents. These
   // properties are either created by this FrameView or are inherited from
   // an ancestor.
   std::unique_ptr<PropertyTreeState> m_totalPropertyTreeStateForContents;
   // Whether the paint properties need to be updated. For more details, see
   // FrameView::needsPaintPropertyUpdate().
   bool m_needsPaintPropertyUpdate;
+  bool m_shouldInvalidateAllPaintAndPaintProperties;
 
   // This is set on the local root frame view only.
   DocumentLifecycle::LifecycleState m_currentUpdateLifecyclePhasesTargetState;
 
   ScrollAnchor m_scrollAnchor;
   using AnchoringAdjustmentQueue =
       HeapLinkedHashSet<WeakMember<ScrollableArea>>;
   AnchoringAdjustmentQueue m_anchoringAdjustmentQueue;
 
   // ScrollbarManager holds the Scrollbar instances.
@@ skipping 49 matching lines @@
                   widget.isFrameView());
 DEFINE_TYPE_CASTS(FrameView,
                   ScrollableArea,
                   scrollableArea,
                   scrollableArea->isFrameView(),
                   scrollableArea.isFrameView());
 
 }  // namespace blink
 
 #endif  // FrameView_h