Add ReferrerPolicy support to preload

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 8884bdda02babbf08b12cce11402e8f9fc123491..202385a00114e8f293e1b4c927a2b6b9eb95b6f3 100644
--- a/third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp
+++ b/third_party/WebKit/Source/core/html/parser/HTMLPreloadScanner.cpp
@@ -357,6 +357,12 @@ class TokenPreloadScanner::StartTagScanner {
     } else if (match(attributeName, typeAttr)) {
       m_matched &= MIMETypeRegistry::isSupportedStyleSheetMIMEType(
           ContentType(attributeValue).type());
+    } else if (!m_referrerPolicySet &&
+               match(attributeName, referrerpolicyAttr) &&
+               !attributeValue.isNull()) {
+      m_referrerPolicySet = true;
+      SecurityPolicy::referrerPolicyFromStringWithLegacyKeywords(
+          attributeValue, &m_referrerPolicy);
     }
   }