Remove out-of-date comment about scoped style resolvers.

third_party/WebKit/Source/core/dom/StyleEngine.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 554 matching lines @@
   styleSheet->contents()->parseStringAtPosition(text, startPosition);
   return styleSheet;
 }
 
 void StyleEngine::collectScopedStyleFeaturesTo(RuleFeatureSet& features) const {
   HeapHashSet<Member<const StyleSheetContents>> visitedSharedStyleSheetContents;
   if (document().scopedStyleResolver())
     document().scopedStyleResolver()->collectFeaturesTo(
         features, visitedSharedStyleSheetContents);
   for (TreeScope* treeScope : m_activeTreeScopes) {
-    // When creating StyleResolver, dirty treescopes might not be processed.
-    // So some active treescopes might not have a scoped style resolver.
-    // In this case, we should skip collectFeatures for the treescopes without
-    // scoped style resolvers. When invoking updateActiveStyleSheets,
-    // the treescope's features will be processed.
     if (ScopedStyleResolver* resolver = treeScope->scopedStyleResolver())
       resolver->collectFeaturesTo(features, visitedSharedStyleSheetContents);
   }
 }
 
 void StyleEngine::fontsNeedUpdate(CSSFontSelector*) {
   if (!document().isActive())
     return;
 
   if (m_resolver)
@@ skipping 564 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(StyleEngine) {
   for (auto sheet : m_injectedAuthorStyleSheets) {
     visitor->traceWrappers(sheet);
   }
   visitor->traceWrappers(m_documentStyleSheetCollection);
 }
 
 }  // namespace blink