Remove stylesheet injection from Blink.

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)
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
@@ skipping 64 matching lines @@
             engine.selectStylesheetSetName(candidate.title());
         collector.appendSheetForList(sheet);
         if (candidate.canBeActivated(engine.preferredStylesheetSetName()))
             collector.appendActiveStyleSheet(toCSSStyleSheet(sheet));
     }
 }
 
 void DocumentStyleSheetCollection::collectStyleSheets(StyleEngine& engine, DocumentStyleSheetCollector& collector)
 {
     ASSERT(&document().styleEngine() == &engine);
-    collector.appendActiveStyleSheets(engine.injectedAuthorStyleSheets());
     collector.appendActiveStyleSheets(engine.documentAuthorStyleSheets());
     collectStyleSheetsFromCandidates(engine, collector);
 }
 
 void DocumentStyleSheetCollection::updateActiveStyleSheets(StyleEngine& engine, StyleResolverUpdateMode updateMode)
 {
     StyleSheetCollection collection;
     ActiveDocumentStyleSheetCollector collector(collection);
     collectStyleSheets(engine, collector);
 
@@ skipping 18 matching lines @@
     }
     if (change.requiresFullStyleRecalc)
         document().setNeedsStyleRecalc(SubtreeStyleChange, StyleChangeReasonForTracing::create(StyleChangeReason::ActiveStylesheetsUpdate));
 
     collection.swap(*this);
 
     updateUsesRemUnits();
 }
 
 }