Limit <link rel=preconnect> to the HTTP family

Source/core/loader/LinkLoader.cpp

Index: Source/core/loader/LinkLoader.cpp
diff --git a/Source/core/loader/LinkLoader.cpp b/Source/core/loader/LinkLoader.cpp
index 5fd7b7011aec1e6ecf21dcaeb723d4d1f8c98740..b5b81e5e978d2d73ab55a3f5e4d7cc0c3395d02c 100644
--- a/Source/core/loader/LinkLoader.cpp
+++ b/Source/core/loader/LinkLoader.cpp
@@ -131,7 +131,7 @@ static void dnsPrefetchIfNeeded(const LinkRelAttribute& relAttribute, const KURL
 
 static void preconnectIfNeeded(const LinkRelAttribute& relAttribute, const KURL& href, Document& document, const CrossOriginAttributeValue crossOrigin)
 {
-    if (relAttribute.isPreconnect() && href.isValid()) {
+    if (relAttribute.isPreconnect() && href.isValid() && href.protocolIsInHTTPFamily()) {
         ASSERT(RuntimeEnabledFeatures::linkPreconnectEnabled());
         Settings* settings = document.settings();
         if (settings && settings->logDnsPrefetchAndPreconnect()) {