Collect media query results for non-matching stylesheets.

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 1081 matching lines @@
     return;
 
   if (!tree_scope.GetDocument().body() ||
       tree_scope.GetDocument().HasNodesWithPlaceholderStyle()) {
     tree_scope.GetDocument().SetNeedsStyleRecalc(
         kSubtreeStyleChange, StyleChangeReasonForTracing::Create(
                                  StyleChangeReason::kCleanupPlaceholderStyles));
     return;
   }
 
+  if (changed_rule_sets.IsEmpty())
+    return;
+
   if (changed_rule_flags & kKeyframesRules)
     ScopedStyleResolver::KeyframesRulesAdded(tree_scope);
 
   Node& invalidation_root =
       ScopedStyleResolver::InvalidationRootForTreeScope(tree_scope);
   if (invalidation_root.GetStyleChangeType() >= kSubtreeStyleChange)
     return;
 
   if (fonts_changed || (changed_rule_flags & kFullRecalcRules)) {
     invalidation_root.SetNeedsStyleRecalc(
@@ skipping 60 matching lines @@
 }
 
 DEFINE_TRACE_WRAPPERS(StyleEngine) {
   for (auto sheet : injected_author_style_sheets_) {
     visitor->TraceWrappers(sheet);
   }
   visitor->TraceWrappers(document_style_sheet_collection_);
 }
 
 }  // namespace blink