Apply meta tag referrer policy for preloaded requests

Source/core/dom/Document.cpp

Index: Source/core/dom/Document.cpp
diff --git a/Source/core/dom/Document.cpp b/Source/core/dom/Document.cpp
index 8668dd20dee17af73c1de393abae62a90f05e65d..51aa6b792f9c514ff2ba5857f3e05e400fca42c6 100644
--- a/Source/core/dom/Document.cpp
+++ b/Source/core/dom/Document.cpp
@@ -3153,20 +3153,13 @@ void Document::updateViewportDescription()
 
 void Document::processReferrerPolicy(const String& policy)
 {
-    ASSERT(!policy.isNull());
-
-    if (equalIgnoringCase(policy, "no-referrer") || equalIgnoringCase(policy, "never"))
-        setReferrerPolicy(ReferrerPolicyNever);
-    else if (equalIgnoringCase(policy, "unsafe-url") || equalIgnoringCase(policy, "always"))
-        setReferrerPolicy(ReferrerPolicyAlways);
-    else if (equalIgnoringCase(policy, "origin"))
-        setReferrerPolicy(ReferrerPolicyOrigin);
-    else if (equalIgnoringCase(policy, "origin-when-cross-origin") || equalIgnoringCase(policy, "origin-when-crossorigin"))
-        setReferrerPolicy(ReferrerPolicyOriginWhenCrossOrigin);
-    else if (equalIgnoringCase(policy, "no-referrer-when-downgrade") || equalIgnoringCase(policy, "default"))
-        setReferrerPolicy(ReferrerPolicyNoReferrerWhenDowngrade);
-    else
+    ReferrerPolicy referrerPolicy;
+    if (!SecurityPolicy::referrerPolicyFromString(policy, &referrerPolicy)) {
         addConsoleMessage(ConsoleMessage::create(RenderingMessageSource, ErrorMessageLevel, "Failed to set referrer policy: The value '" + policy + "' is not one of 'always', 'default', 'never', 'no-referrer', 'no-referrer-when-downgrade', 'origin', 'origin-when-crossorigin', or 'unsafe-url'. This document's referrer policy has been left unchanged."));
+        return;
+    }
+
+    setReferrerPolicy(referrerPolicy);
 }
 
 String Document::outgoingReferrer()