Apply meta tag referrer policy for preloaded requests

Source/platform/weborigin/SecurityPolicy.h

Index: Source/platform/weborigin/SecurityPolicy.h
diff --git a/Source/platform/weborigin/SecurityPolicy.h b/Source/platform/weborigin/SecurityPolicy.h
index 78eda16bae04b9da52687b3c0c2792e85e4fc34e..e7cc7de1431ccff5caef025a0a69a91f2c6d1f75 100644
--- a/Source/platform/weborigin/SecurityPolicy.h
+++ b/Source/platform/weborigin/SecurityPolicy.h
@@ -64,6 +64,8 @@ public:
 
     static void addOriginTrustworthyWhiteList(PassRefPtr<SecurityOrigin>);
     static bool isOriginWhiteListedTrustworthy(const SecurityOrigin&);
+
+    static bool referrerPolicyFromString(const String& policy, ReferrerPolicy* result);
 };
 
 } // namespace blink