Add <link rel=preconnect> crossorigin attribute (take 2)

Source/core/loader/LinkHeader.cpp

Index: Source/core/loader/LinkHeader.cpp
diff --git a/Source/core/loader/LinkHeader.cpp b/Source/core/loader/LinkHeader.cpp
index ab32f759787f5f2c497567f2f74e955487ca0689..158c022e8668f3ae7a476cda8c7d671707901d87 100644
--- a/Source/core/loader/LinkHeader.cpp
+++ b/Source/core/loader/LinkHeader.cpp
@@ -40,6 +40,11 @@ static bool isValidParameterValueChar(CharType chr)
     return !isWhitespace(chr) && !isValidParameterValueEnd(chr);
 }
 
+static bool isExtensionParameter(LinkHeader::LinkParameterName name)
+{
+    return name > LinkHeader::LinkParameterAnchor;
+}
+
 // Before:
 //
 // <cat.jpg>; rel=preload
@@ -116,6 +121,8 @@ static LinkHeader::LinkParameterName paramterNameFromString(String name)
         return LinkHeader::LinkParameterRel;
     else if (equalIgnoringCase(name, "anchor"))
         return LinkHeader::LinkParameterAnchor;
+    else if (equalIgnoringCase(name, "crossorigin"))
+        return LinkHeader::LinkParameterCrossOrigin;
     return LinkHeader::LinkParameterUnknown;
 }
 
@@ -137,11 +144,10 @@ static bool parseParameterName(CharType*& position, CharType* end, LinkHeader::L
     skipWhile<CharType, isValidParameterNameChar>(position, end);
     CharType* nameEnd = position;
     skipWhile<CharType, isWhitespace>(position, end);
-    if (!skipExactly<CharType>(position, end, '='))
-        return false;
+    bool hasEqual = skipExactly<CharType>(position, end, '=');
     skipWhile<CharType, isWhitespace>(position, end);
     name = paramterNameFromString(String(nameStart, nameEnd - nameStart));
-    return true;
+    return hasEqual || isExtensionParameter(name);
 }
 
 // Before:
@@ -200,8 +206,10 @@ static bool parseParameterValue(CharType*& position, CharType* end, String& valu
     }
     valueEnd = position;
     skipWhile<CharType, isWhitespace>(position, end);
-    if ((!completeQuotes && valueStart == valueEnd) || (position != end && !isValidParameterValueEnd(*position)))
+    if ((!completeQuotes && valueStart == valueEnd) || (position != end && !isValidParameterValueEnd(*position))) {
+        value = String("");
         return false;
+    }
     if (hasQuotes)
         ++valueStart;
     if (completeQuotes)
@@ -217,6 +225,8 @@ void LinkHeader::setValue(LinkParameterName name, String value)
         m_rel = value.lower();
     else if (name == LinkParameterAnchor)
         m_isValid = false;
+    else if (name == LinkParameterCrossOrigin)
+        m_crossOrigin = crossOriginAttributeValue(value);
 }
 
 template <typename CharType>
@@ -228,7 +238,8 @@ static void findNextHeader(CharType*& position, CharType* end)
 
 template <typename CharType>
 LinkHeader::LinkHeader(CharType*& position, CharType* end)
-    : m_isValid(true)
+    : m_crossOrigin(CrossOriginAttributeNotSet)
+    , m_isValid(true)
 {
     if (!parseURL(position, end, m_url)) {
         m_isValid = false;
@@ -250,7 +261,7 @@ LinkHeader::LinkHeader(CharType*& position, CharType* end)
         }
 
         String parameterValue;
-        if (!parseParameterValue(position, end, parameterValue)) {
+        if (!parseParameterValue(position, end, parameterValue) && !isExtensionParameter(parameterName)) {
             findNextHeader(position, end);
             m_isValid = false;
             return;