Perform CORS access checks on Beacon redirects.

Source/core/loader/PingLoader.h

Index: Source/core/loader/PingLoader.h
diff --git a/Source/core/loader/PingLoader.h b/Source/core/loader/PingLoader.h
index fb4f506aeee12f698ad427339777c361c0662c48..69f5da59a5f4e9783b7c7d416f317b9447425610 100644
--- a/Source/core/loader/PingLoader.h
+++ b/Source/core/loader/PingLoader.h
@@ -79,6 +79,8 @@ protected:
 
     static void start(LocalFrame*, ResourceRequest&, const FetchInitiatorInfo&, StoredCredentials = AllowStoredCredentials);
 
+    void dispose();
+
 private:
     virtual void didReceiveResponse(blink::WebURLLoader*, const blink::WebURLResponse&) override;
     virtual void didReceiveData(blink::WebURLLoader*, const char*, int, int) override;
@@ -89,8 +91,6 @@ private:
 
     void didFailLoading(Page*);
 
-    void dispose();
-
     OwnPtr<blink::WebURLLoader> m_loader;
     Timer<PingLoader> m_timeout;
     String m_url;