Anchor element's referrer attribute implementation for Referrer Policy

Source/platform/weborigin/ReferrerPolicy.h

Index: Source/platform/weborigin/ReferrerPolicy.h
diff --git a/Source/platform/weborigin/ReferrerPolicy.h b/Source/platform/weborigin/ReferrerPolicy.h
index 0f2bd29296fc4a49009b209269d616bb4a10f86f..c34e67d56072bf6ff8c2f2cf9713096e587848bf 100644
--- a/Source/platform/weborigin/ReferrerPolicy.h
+++ b/Source/platform/weborigin/ReferrerPolicy.h
@@ -32,6 +32,8 @@
 #ifndef ReferrerPolicy_h
 #define ReferrerPolicy_h
 
+#include "wtf/text/WTFString.h"
+
 namespace blink {
 
 enum ReferrerPolicy {
@@ -46,9 +48,13 @@ enum ReferrerPolicy {
     // https://w3c.github.io/webappsec/specs/referrer-policy/#referrer-policy-state-origin
     ReferrerPolicyOrigin,
     // https://w3c.github.io/webappsec/specs/referrer-policy/#referrer-policy-state-origin-when-cross-origin
-    ReferrerPolicyOriginWhenCrossOrigin,
+    ReferrerPolicyOriginWhenCrossOrigin
 };
 
+bool ParseReferrerPolicy(const WTF::String&, ReferrerPolicy*);
+
+WTF::String ReferrerPolicyToString(ReferrerPolicy);
+
 }
 
 #endif // ReferrerPolicy_h