setNeedsPaintPropertyUpdate on FrameView contents size change

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

 /*
  * Copyright (C) 1998, 1999 Torben Weis <weis@kde.org>
  *                     1999 Lars Knoll <knoll@kde.org>
  *                     1999 Antti Koivisto <koivisto@kde.org>
  *                     2000 Dirk Mueller <mueller@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *           (C) 2006 Graham Dennis (graham.dennis@gmail.com)
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
@@ skipping 618 matching lines @@
 }
 
 void FrameView::setContentsSize(const IntSize& size) {
   if (size == contentsSize())
     return;
 
   m_contentsSize = size;
   updateScrollbars();
   ScrollableArea::contentsResized();
 
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled() &&
+      !RuntimeEnabledFeatures::rootLayerScrollingEnabled())
+    setNeedsPaintPropertyUpdate();
+
   Page* page = frame().page();
   if (!page)
     return;
 
   updateParentScrollableAreaSet();
 
   page->chromeClient().contentsSizeChanged(m_frame.get(), size);
   frame().loader().restoreScrollPositionAndViewState();
 }
 
@@ skipping 4003 matching lines @@
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.width();
 }
 
 int FrameView::initialViewportHeight() const {
   DCHECK(m_frame->isMainFrame());
   return m_initialViewportSize.height();
 }
 
 }  // namespace blink