Revert of Revert of Never send a referrer header if the referrer is not a web url

Source/platform/weborigin/SecurityPolicy.cpp

Index: Source/platform/weborigin/SecurityPolicy.cpp
diff --git a/Source/platform/weborigin/SecurityPolicy.cpp b/Source/platform/weborigin/SecurityPolicy.cpp
index 6c48c68394398e5cd46ded85566dd2e8bd8fddf5..e9d717f30d4a04571d1a81d83dfd7865fe2d3772 100644
--- a/Source/platform/weborigin/SecurityPolicy.cpp
+++ b/Source/platform/weborigin/SecurityPolicy.cpp
@@ -68,6 +68,9 @@
 String SecurityPolicy::generateReferrerHeader(ReferrerPolicy referrerPolicy, const KURL& url, const String& referrer)
 {
     if (referrer.isEmpty())
+        return String();
+
+    if (!(protocolIs(referrer, "https") || protocolIs(referrer, "http")))
         return String();
 
     switch (referrerPolicy) {