Repaint selection when element with ::selection style is recalculated.

third_party/WebKit/Source/core/style/StyleDifference.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef StyleDifference_h
 #define StyleDifference_h
 
 #include "wtf/Allocator.h"
 #include "wtf/Assertions.h"
 
@@ skipping 37 matching lines @@
   bool hasAtMostPropertySpecificDifferences(
       unsigned propertyDifferences) const {
     return !m_paintInvalidationType && !m_layoutType &&
            !(m_propertySpecificDifferences & ~propertyDifferences);
   }
 
   bool needsPaintInvalidation() const {
     return m_paintInvalidationType != NoPaintInvalidation;
   }
 
+  // The text selection needs paint invalidation.
+  bool needsPaintInvalidationSelection() const {
+    return m_paintInvalidationType == PaintInvalidationSelection;
+  }
+  void setNeedsPaintInvalidationSelection() {
+    DCHECK(!needsPaintInvalidation());

[mstensho (USE GERRIT), 2017/02/21 21:03:54]

So, it looks like this one is failing in quite a few tests.

[rune, 2017/02/21 21:42:00]

Yes. This is fragile since it relies on order and logic in
visualInvalidationDiff(). I've mad this an if-test in PS2 instead.

+    m_paintInvalidationType = PaintInvalidationSelection;
+  }
+
   // The object just needs to issue paint invalidations.
   bool needsPaintInvalidationObject() const {
     return m_paintInvalidationType == PaintInvalidationObject;
   }
   void setNeedsPaintInvalidationObject() {
-    ASSERT(!needsPaintInvalidationSubtree());
+    DCHECK(!needsPaintInvalidationSubtree());
     m_paintInvalidationType = PaintInvalidationObject;
   }
 
   // The object and its descendants need to issue paint invalidations.
   bool needsPaintInvalidationSubtree() const {
     return m_paintInvalidationType == PaintInvalidationSubtree;
   }
   void setNeedsPaintInvalidationSubtree() {
     m_paintInvalidationType = PaintInvalidationSubtree;
   }
@@ skipping 59 matching lines @@
 
   bool scrollAnchorDisablingPropertyChanged() const {
     return m_scrollAnchorDisablingPropertyChanged;
   }
   void setScrollAnchorDisablingPropertyChanged() {
     m_scrollAnchorDisablingPropertyChanged = true;
   }
 
  private:
   enum PaintInvalidationType {
-    NoPaintInvalidation = 0,
+    NoPaintInvalidation,
+    PaintInvalidationSelection,
     PaintInvalidationObject,
-    PaintInvalidationSubtree
+    PaintInvalidationSubtree,
   };
   unsigned m_paintInvalidationType : 2;
 
   enum LayoutType { NoLayout = 0, PositionedMovement, FullLayout };
   unsigned m_layoutType : 2;
   unsigned m_recomputeOverflow : 1;
   unsigned m_propertySpecificDifferences : 7;
   unsigned m_scrollAnchorDisablingPropertyChanged : 1;
 };
 
 }  // namespace blink
 
 #endif  // StyleDifference_h