Collect active stylesheets and and apply asynchronously.

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 552 matching lines @@
   return *m_selectorQueryCache;
 }
 
 MediaQueryMatcher& Document::mediaQueryMatcher() {
   if (!m_mediaQueryMatcher)
     m_mediaQueryMatcher = MediaQueryMatcher::create(*this);
   return *m_mediaQueryMatcher;
 }
 
 void Document::mediaQueryAffectingValueChanged() {
-  m_evaluateMediaQueriesOnStyleRecalc = true;
   styleEngine().mediaQueryAffectingValueChanged();
+  if (needsLayoutTreeUpdate())
+    m_evaluateMediaQueriesOnStyleRecalc = true;
+  else
+    evaluateMediaQueryList();
   InspectorInstrumentation::mediaQueryResultChanged(this);
 }
 
 void Document::setCompatibilityMode(CompatibilityMode mode) {
   if (m_compatibilityModeLocked || mode == m_compatibilityMode)
     return;
   m_compatibilityMode = mode;
   selectorQueryCache().invalidate();
 }
 
@@ skipping 1635 matching lines @@
     // stop it a second time, after page content has already been loaded and
     // displayed with accurate style information. (Our suppression involves
     // blanking the whole page at the moment. If it were more refined, we might
     // be able to do something better.) It's worth noting though that this
     // entire method is a hack, since what we really want to do is suspend JS
     // instead of doing a layout with inaccurate information.
     HTMLElement* bodyElement = body();
     if (bodyElement && !bodyElement->layoutObject() &&
         m_pendingSheetLayout == NoLayoutWithPendingSheets) {
       m_pendingSheetLayout = DidLayoutWithPendingSheets;
-      styleEngine().resolverChanged(FullStyleUpdate);
-    } else if (m_hasNodesWithPlaceholderStyle) {
+      styleEngine().markAllTreeScopesDirty();
+    }
+    if (m_hasNodesWithPlaceholderStyle) {
       // If new nodes have been added or style recalc has been done with style
       // sheets still pending, some nodes may not have had their real style
       // calculated yet.  Normally this gets cleaned when style sheets arrive
       // but here we need up-to-date style immediately.
       setNeedsStyleRecalc(SubtreeStyleChange,
                           StyleChangeReasonForTracing::create(
                               StyleChangeReason::CleanupPlaceholderStyles));
     }
   }
   updateStyleAndLayoutTree();
@@ skipping 4339 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