[SPInvalidation] Invalidate all paint and properties for printing

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

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index f3496595a49b91242f2929265d357eb26dab8317..d0946ae4bea708f14685b5ccd0fec2e86065f2fa 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -748,6 +748,19 @@ class CORE_EXPORT FrameView final
     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();
 
@@ -1103,6 +1116,7 @@ class CORE_EXPORT FrameView final
   // 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;