Make calls to AtomicString(const String&) explicit in loader/ and fetch/

Source/core/loader/PingLoader.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 67 matching lines @@
     request.setHTTPBody(FormData::create("PING"));
     request.setHTTPHeaderField("Cache-Control", "max-age=0");
     frame->loader().fetchContext().addAdditionalRequestHeaders(frame->document(), request, FetchSubresource);
 
     RefPtr<SecurityOrigin> pingOrigin = SecurityOrigin::create(pingURL);
     // addAdditionalRequestHeaders() will have added a referrer for same origin requests,
     // but the spec omits the referrer for same origin.
     if (frame->document()->securityOrigin()->isSameSchemeHostPort(pingOrigin.get()))
         request.clearHTTPReferrer();
 
-    request.setHTTPHeaderField("Ping-To", destinationURL.string());
+    request.setHTTPHeaderField("Ping-To", AtomicString(destinationURL.string()));
 
     // Ping-From follows the same rules as the default referrer beahavior for subresource requests.
     // FIXME: Should Ping-From obey ReferrerPolicy?
     if (!SecurityPolicy::shouldHideReferrer(pingURL, frame->document()->url().string()))
-        request.setHTTPHeaderField("Ping-From", frame->document()->url().string());
+        request.setHTTPHeaderField("Ping-From", AtomicString(frame->document()->url().string()));
     OwnPtr<PingLoader> pingLoader = adoptPtr(new PingLoader(frame, request));
 
     // Leak the ping loader, since it will kill itself as soon as it receives a response.
     PingLoader* ALLOW_UNUSED leakedPingLoader = pingLoader.leakPtr();
 }
 
 void PingLoader::sendViolationReport(Frame* frame, const KURL& reportURL, PassRefPtr<FormData> report, ViolationReportType type)
 {
     ResourceRequest request(reportURL);
     request.setTargetType(ResourceRequest::TargetIsSubresource);
@@ skipping 26 matching lines @@
     m_timeout.startOneShot(60000);
 }
 
 PingLoader::~PingLoader()
 {
     if (m_loader)
         m_loader->cancel();
 }
 
 }