Mark when we may have been invalidated to early out on repaintTreeAfterLayout.

Source/core/rendering/RenderDeprecatedFlexibleBox.cpp

 /*
  * This file is part of the render object implementation for KHTML.
  *
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 981 matching lines @@
                 toRenderBlock(child)->clearTruncation();
             }
         }
     }
 }
 
 void RenderDeprecatedFlexibleBox::placeChild(RenderBox* child, const LayoutPoint& location)
 {
     LayoutRect oldRect = child->frameRect();
 
+    // FIXME Investigate if this can be removed based on other flags. crbug.com/370010
+    child->setMayNeedInvalidation(true);
+
     // Place the child.
     child->setLocation(location);
 
     // If the child moved, we have to repaint it as well as any floating/positioned
     // descendants.  An exception is if we need a layout.  In this case, we know we're going to
     // repaint ourselves (and the child) anyway.
     if (!selfNeedsLayout() && child->checkForRepaintDuringLayout())
         child->repaintDuringLayoutIfMoved(oldRect);
 }
 
@@ skipping 66 matching lines @@
     if (isPseudoElement())
         return "RenderDeprecatedFlexibleBox (generated)";
     if (isAnonymous())
         return "RenderDeprecatedFlexibleBox (generated)";
     if (isRelPositioned())
         return "RenderDeprecatedFlexibleBox (relative positioned)";
     return "RenderDeprecatedFlexibleBox";
 }
 
 } // namespace WebCore