No need to re-collect stylesheets for setting type StyleChange.

third_party/WebKit/Source/core/page/Page.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 Apple Inc. All Rights Reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 #include "core/page/Page.h"
 
 #include "core/css/resolver/ViewportStyleResolver.h"
 #include "core/dom/ClientRectList.h"
+#include "core/dom/StyleChangeReason.h"
 #include "core/dom/VisitedLinkState.h"
 #include "core/editing/DragCaretController.h"
 #include "core/editing/commands/UndoStack.h"
 #include "core/editing/markers/DocumentMarkerController.h"
 #include "core/events/Event.h"
 #include "core/fetch/MemoryCache.h"
 #include "core/fetch/ResourceFetcher.h"
 #include "core/frame/DOMTimer.h"
 #include "core/frame/FrameConsole.h"
 #include "core/frame/FrameHost.h"
@@ skipping 200 matching lines @@
         for (Frame* frame = page->mainFrame(); frame; frame = frame->tree().traverseNext()) {
             if (frame->isLocalFrame())
                 toLocalFrame(frame)->document()->platformColorsChanged();
         }
 }
 
 void Page::setNeedsRecalcStyleInAllFrames()
 {
     for (Frame* frame = mainFrame(); frame; frame = frame->tree().traverseNext()) {
         if (frame->isLocalFrame())
-            toLocalFrame(frame)->document()->styleEngine().resolverChanged(FullStyleUpdate);
+            toLocalFrame(frame)->document()->setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::Settings));
     }
 }
 
 void Page::refreshPlugins()
 {
     if (allPages().isEmpty())
         return;
 
     PluginData::refresh();
 
@@ skipping 352 matching lines @@
 {
 }
 
 Page::PageClients::~PageClients()
 {
 }
 
 template class CORE_TEMPLATE_EXPORT WillBeHeapSupplement<Page>;
 
 } // namespace blink