Document lifecycle violation

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 2524 matching lines @@
     for (Frame* child = m_frame->tree().firstChild(); child; child = child->tree().nextSibling()) {
         if (!child->isLocalFrame())
             continue;
         if (FrameView* view = toLocalFrame(child)->view())
             frameViews.append(view);
     }
 
     for (const auto& frameView : frameViews)
         frameView->updateStyleAndLayoutIfNeededRecursive();
 
-    // When an <iframe> gets composited, it triggers an extra style recalc in its containing FrameView.
-    // To avoid pushing an invalid tree for display, we have to check for this case and do another
-    // style recalc. The extra style recalc needs to happen after our child <iframes> were updated.
-    // FIXME: We shouldn't be triggering an extra style recalc in the first place.
+    // When SVG filters are invalidated using Document::scheduleSVGFilterLayerUpdateHack() they may require an
+    // extra layout tree update.
     if (m_frame->document()->hasSVGFilterElementsRequiringLayerUpdate()) {
         m_frame->document()->updateLayoutTreeIfNeeded();
 
         if (needsLayout())
             layout();
     }
 
     // These asserts ensure that parent frames are clean, when child frames finished updating layout and style.
     ASSERT(!needsLayout());
     ASSERT(!m_frame->document()->hasSVGFilterElementsRequiringLayerUpdate());
@@ skipping 1450 matching lines @@
     return m_hiddenForThrottling && m_crossOriginForThrottling;
 }
 
 LayoutBox& FrameView::boxForScrollControlPaintInvalidation() const
 {
     ASSERT(layoutView());
     return *layoutView();
 }
 
 } // namespace blink