Remove fetching stylesheets with unsupported type

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

Index: third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp
diff --git a/third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp b/third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp
index f63662243e6220bcbb6a5fd308f3ab3bcabc132b..d16ff0d63d1027e65119a5d636a74c703871a68d 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp
+++ b/third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp
@@ -45,6 +45,8 @@
 #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"
@@ -116,6 +118,8 @@ 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)
@@ -280,6 +284,9 @@ private:
             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.

         }
     }
 
@@ -392,6 +399,8 @@ private:
             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;
@@ -416,6 +425,8 @@ private:
     ImageCandidate m_srcsetImageCandidate;
     String m_charset;
     bool m_linkIsStyleSheet;
+    bool m_linkHasType;
+    bool m_linkTypeIsSupportedStyleSheet;
     bool m_linkIsPreconnect;
     bool m_linkIsPreload;
     bool m_linkIsImport;