No forced active stylesheet recollect when pending sheets reach 0.

third_party/WebKit/Source/core/dom/Document.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2011, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2008, 2009, 2011, 2012 Google Inc. All rights reserved.
@@ skipping 3658 matching lines @@
 
 void Document::notifyResizeForViewportUnits() {
   if (m_mediaQueryMatcher)
     m_mediaQueryMatcher->viewportChanged();
   if (!hasViewportUnits())
     return;
   ensureStyleResolver().notifyResizeForViewportUnits();
   setNeedsStyleRecalcForViewportUnits();
 }
 
 void Document::styleResolverMayHaveChanged() {

[rune, 2016/11/15 10:39:03]

This is a confusing name for this method, but I haven't found a good name for it
yet. It means something along the lines of:

invalidateStyleUpdateActiveStyleSheetsAndMakeSureSuppressedPaintInvalidationsTriggerAfter(Script/Render)BlockingResourcesFinishedLoading();

[meade_UTC10, 2016/11/16 18:10:31]

D: 

-  styleEngine().resolverChanged(
-      hasNodesWithPlaceholderStyle() ? FullStyleUpdate : AnalyzedStyleUpdate);
+  styleEngine().resolverChanged(AnalyzedStyleUpdate);
+
+  if (hasNodesWithPlaceholderStyle()) {
+    setNeedsStyleRecalc(SubtreeStyleChange,
+                        StyleChangeReasonForTracing::create(
+                            StyleChangeReason::CleanupPlaceholderStyles));
+  }
 
   if (didLayoutWithPendingStylesheets() &&
       !styleEngine().hasPendingScriptBlockingSheets()) {
     // We need to manually repaint because we avoid doing all repaints in layout
     // or style recalc while sheets are still loading to avoid FOUC.
     m_pendingSheetLayout = IgnoreLayoutWithPendingSheets;
 
     DCHECK(!layoutViewItem().isNull() || importsController());
     if (!layoutViewItem().isNull())
       layoutViewItem().invalidatePaintForViewAndCompositedLayers();
@@ skipping 2745 matching lines @@
 }
 
 void showLiveDocumentInstances() {
   WeakDocumentSet& set = liveDocumentSet();
   fprintf(stderr, "There are %u documents currently alive:\n", set.size());
   for (Document* document : set)
     fprintf(stderr, "- Document %p URL: %s\n", document,
             document->url().getString().utf8().data());
 }
 #endif