Provide a method to remove inserted style sheet

third_party/WebKit/Source/core/dom/DocumentStyleSheetCollection.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, 2010, 2012 Apple Inc. All
  * rights reserved.
  * Copyright (C) 2008, 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
@@ skipping 76 matching lines @@
         std::make_pair(css_sheet, master_engine.RuleSetForSheet(*css_sheet)));
   }
 }
 
 void DocumentStyleSheetCollection::CollectStyleSheets(
     StyleEngine& master_engine,
     DocumentStyleSheetCollector& collector) {
   for (auto& sheet :
        GetDocument().GetStyleEngine().InjectedAuthorStyleSheets()) {
     collector.AppendActiveStyleSheet(std::make_pair(
-        sheet, GetDocument().GetStyleEngine().RuleSetForSheet(*sheet)));
+        sheet.second,
+        GetDocument().GetStyleEngine().RuleSetForSheet(*sheet.second)));
   }
   CollectStyleSheetsFromCandidates(master_engine, collector);
   if (CSSStyleSheet* inspector_sheet =
           GetDocument().GetStyleEngine().InspectorStyleSheet()) {
     collector.AppendActiveStyleSheet(std::make_pair(
         inspector_sheet,
         GetDocument().GetStyleEngine().RuleSetForSheet(*inspector_sheet)));
   }
 }
 
@@ skipping 18 matching lines @@
       continue;
     if (!candidate.CanBeActivated(
             GetDocument().GetStyleEngine().PreferredStylesheetSetName()))
       continue;
     viewport_resolver.CollectViewportRulesFromAuthorSheet(
         *ToCSSStyleSheet(sheet));
   }
 }
 
 }  // namespace blink