CSS: Drop the quirks-mode exception for CSS MIME types.

Source/core/css/StyleSheetContents.cpp

 /*
  * (C) 1999-2003 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2004, 2006, 2007, 2012 Apple Inc. All rights reserved.
  *
  * 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,
@@ skipping 265 matching lines @@
     if (prefix == starAtom)
         return starAtom; // We'll match any namespace.
     return m_namespaces.get(prefix);
 }
 
 void StyleSheetContents::parseAuthorStyleSheet(const CSSStyleSheetResource* cachedStyleSheet, const SecurityOrigin* securityOrigin)
 {
     TRACE_EVENT0("blink", "StyleSheetContents::parseAuthorStyleSheet");
     TRACE_EVENT1(TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "ParseAuthorStyleSheet", "data", InspectorParseAuthorStyleSheetEvent::data(cachedStyleSheet));
 
-    bool quirksMode = isQuirksModeBehavior(m_parserContext.mode());
-
-    bool enforceMIMEType = !quirksMode;
     bool hasValidMIMEType = false;
-    String sheetText = cachedStyleSheet->sheetText(enforceMIMEType, &hasValidMIMEType);
+    String sheetText = cachedStyleSheet->sheetText(&hasValidMIMEType);
 
     const ResourceResponse& response = cachedStyleSheet->response();
     m_sourceMapURL = response.httpHeaderField("SourceMap");
     if (m_sourceMapURL.isEmpty()) {
         // Try to get deprecated header.
         m_sourceMapURL = response.httpHeaderField("X-SourceMap");
     }
 
     CSSParserContext context(parserContext(), UseCounter::getFrom(this));
     CSSParser::parseSheet(context, this, sheetText, TextPosition::minimumPosition(), 0, true);
@@ skipping 354 matching lines @@
     visitor->trace(m_ownerRule);
     visitor->trace(m_importRules);
     visitor->trace(m_childRules);
     visitor->trace(m_loadingClients);
     visitor->trace(m_completedClients);
     visitor->trace(m_ruleSet);
 #endif
 }
 
 }