Remove fetching stylesheets with unsupported type

third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2009 Torch Mobile, Inc. http://www.torchmobile.com/
  * Copyright (C) 2010 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 27 matching lines @@
 #include "core/frame/Settings.h"
 #include "core/frame/SubresourceIntegrity.h"
 #include "core/html/CrossOriginAttribute.h"
 #include "core/html/HTMLImageElement.h"
 #include "core/html/HTMLMetaElement.h"
 #include "core/html/LinkRelAttribute.h"
 #include "core/html/parser/HTMLParserIdioms.h"
 #include "core/html/parser/HTMLSrcsetParser.h"
 #include "core/html/parser/HTMLTokenizer.h"
 #include "core/loader/LinkLoader.h"
+#include "platform/ContentType.h"
+#include "platform/MIMETypeRegistry.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/TraceEvent.h"
 #include "wtf/MainThread.h"
 
 namespace blink {
 
 using namespace HTMLNames;
 
 static bool match(const StringImpl* impl, const QualifiedName& qName)
 {
@@ skipping 51 matching lines @@
     MediaQueryEvaluator mediaQueryEvaluator(mediaValues);
     return mediaQueryEvaluator.eval(mediaQueries.get());
 }
 
 class TokenPreloadScanner::StartTagScanner {
     STACK_ALLOCATED();
 public:
     StartTagScanner(const StringImpl* tagImpl, PassRefPtrWillBeRawPtr<MediaValues> mediaValues)
         : m_tagImpl(tagImpl)
         , m_linkIsStyleSheet(false)
+        , m_linkHasType(false)
+        , m_linkTypeIsSupportedStyleSheet(false)
         , m_linkIsPreconnect(false)
         , m_linkIsPreload(false)
         , m_linkIsImport(false)
         , m_matchedMediaAttribute(true)
         , m_inputIsImage(false)
         , m_sourceSize(0)
         , m_sourceSizeSet(false)
         , m_defer(FetchRequest::NoDefer)
         , m_crossOrigin(CrossOriginAttributeNotSet)
         , m_mediaValues(mediaValues)
@@ skipping 144 matching lines @@
             m_linkIsStyleSheet = rel.isStyleSheet() && !rel.isAlternate() && rel.iconType() == InvalidIcon && !rel.isDNSPrefetch();
             m_linkIsPreconnect = rel.isPreconnect();
             m_linkIsPreload = rel.isLinkPreload();
             m_linkIsImport = rel.isImport();
         } else if (match(attributeName, mediaAttr)) {
             m_matchedMediaAttribute = mediaAttributeMatches(*m_mediaValues, attributeValue);
         } else if (match(attributeName, crossoriginAttr)) {
             setCrossOrigin(attributeValue);
         } else if (match(attributeName, asAttr)) {
             m_asAttributeValue = attributeValue;
+        } else if (match(attributeName, typeAttr)) {
+            m_linkHasType = true;
+            m_linkTypeIsSupportedStyleSheet = MIMETypeRegistry::isSupportedStyleSheetMIMEType(ContentType(attributeValue).type());

[Yoav Weiss, 2016/01/25 09:55:54]

I don't think we need two booleans here. You could change this to
m_linkTypeIsMissingOrSupportedStyleSheet, and initialize it to true.

[suzyh_UTC10 (ex-contributor), 2016/01/27 00:07:53]

Done.

         }
     }
 
     template<typename NameType>
     void processInputAttribute(const NameType& attributeName, const String& attributeValue)
     {
         // FIXME - Don't set type multiple times.
         if (match(attributeName, srcAttr))
             setUrlToLoad(attributeValue, DisallowURLReplacement);
         else if (match(attributeName, typeAttr))
@@ skipping 92 matching lines @@
     {
         return match(m_tagImpl, linkTag) && m_linkIsPreload && !m_urlToLoad.isEmpty();
     }
 
     bool shouldPreload() const
     {
         if (m_urlToLoad.isEmpty())
             return false;
         if (match(m_tagImpl, linkTag) && !m_linkIsStyleSheet && !m_linkIsImport && !m_linkIsPreload)
             return false;
+        if (match(m_tagImpl, linkTag) && m_linkIsStyleSheet && m_linkHasType && !m_linkTypeIsSupportedStyleSheet)
+            return false;
         if (match(m_tagImpl, inputTag) && !m_inputIsImage)
             return false;
         return true;
     }

[Yoav Weiss, 2016/01/25 09:55:54]

Nit: Could you add a new line here, since you're already editing this area?

[suzyh_UTC10 (ex-contributor), 2016/01/27 00:07:53]

Done.

     void setCrossOrigin(const String& corsSetting)
     {
         m_crossOrigin = crossOriginAttributeValue(corsSetting);
     }
 
     void setDefer(FetchRequest::DeferOption defer)
     {
         m_defer = defer;
     }
 
     bool defer() const
     {
         return m_defer;
     }
 
     const StringImpl* m_tagImpl;
     String m_urlToLoad;
     ImageCandidate m_srcsetImageCandidate;
     String m_charset;
     bool m_linkIsStyleSheet;
+    bool m_linkHasType;
+    bool m_linkTypeIsSupportedStyleSheet;
     bool m_linkIsPreconnect;
     bool m_linkIsPreload;
     bool m_linkIsImport;
     bool m_matchedMediaAttribute;
     bool m_inputIsImage;
     String m_imgSrcUrl;
     String m_srcsetAttributeValue;
     String m_asAttributeValue;
     float m_sourceSize;
     bool m_sourceSizeSet;
@@ skipping 253 matching lines @@
     else
         mediaValues = MediaValuesCached::create(*document);
     ASSERT(mediaValues->isSafeToSendToAnotherThread());
     defaultViewportMinWidth = document->viewportDefaultMinWidth();
     viewportMetaZeroValuesQuirk = document->settings() && document->settings()->viewportMetaZeroValuesQuirk();
     viewportMetaEnabled = document->settings() && document->settings()->viewportMetaEnabled();
     referrerPolicy = ReferrerPolicyDefault;
 }
 
 }