Cheaper thread-safe atomic initialization of static references.

Source/core/fetch/CrossOriginAccessControl.cpp

 /*
  * Copyright (C) 2008 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 39 matching lines @@
     headerSet->add("content-type");
     headerSet->add("expires");
     headerSet->add("last-modified");
     headerSet->add("pragma");
 
     return headerSet.release();
 }
 
 bool isOnAccessControlResponseHeaderWhitelist(const String& name)
 {
-    AtomicallyInitializedStatic(HTTPHeaderSet*, allowedCrossOriginResponseHeaders = createAllowedCrossOriginResponseHeadersSet().leakPtr());
+    AtomicallyInitializedStaticReference(HTTPHeaderSet, allowedCrossOriginResponseHeaders, (createAllowedCrossOriginResponseHeadersSet().leakPtr()));
 
-    return allowedCrossOriginResponseHeaders->contains(name);
+    return allowedCrossOriginResponseHeaders.contains(name);
 }
 
 void updateRequestForAccessControl(ResourceRequest& request, SecurityOrigin* securityOrigin, StoredCredentials allowCredentials)
 {
     request.removeCredentials();
     request.setAllowStoredCredentials(allowCredentials == AllowStoredCredentials);
     request.setFetchCredentialsMode(allowCredentials == AllowStoredCredentials ? WebURLRequest::FetchCredentialsModeInclude : WebURLRequest::FetchCredentialsModeOmit);
 
     if (securityOrigin)
         request.setHTTPOrigin(securityOrigin->toAtomicString());
@@ skipping 38 matching lines @@
 static bool isInterestingStatusCode(int statusCode)
 {
     // Predicate that gates what status codes should be included in
     // console error messages for responses containing no access
     // control headers.
     return statusCode >= 400;
 }
 
 bool passesAccessControlCheck(ExecutionContext* context, const ResourceResponse& response, StoredCredentials includeCredentials, SecurityOrigin* securityOrigin, String& errorDescription)
 {
-    AtomicallyInitializedStatic(AtomicString&, accessControlAllowOrigin = *new AtomicString("access-control-allow-origin", AtomicString::ConstructFromLiteral));
-    AtomicallyInitializedStatic(AtomicString&, accessControlAllowCredentials = *new AtomicString("access-control-allow-credentials", AtomicString::ConstructFromLiteral));
+    AtomicallyInitializedStaticReference(AtomicString, accessControlAllowOrigin, (new AtomicString("access-control-allow-origin", AtomicString::ConstructFromLiteral)));
+    AtomicallyInitializedStaticReference(AtomicString, accessControlAllowCredentials, (new AtomicString("access-control-allow-credentials", AtomicString::ConstructFromLiteral)));
 
     if (!response.httpStatusCode()) {
         errorDescription = "Received an invalid response. Origin '" + securityOrigin->toString() + "' is therefore not allowed access.";
         return false;
     }
 
     const AtomicString& accessControlOriginString = response.httpHeaderField(accessControlAllowOrigin);
     if (accessControlOriginString == starAtom) {
         // A wildcard Access-Control-Allow-Origin can not be used if credentials are to be sent,
         // even with Access-Control-Allow-Credentials set to true.
@@ skipping 112 matching lines @@
         request.setHTTPOrigin(securityOrigin->toAtomicString());
         // If the user didn't request credentials in the first place, update our
         // state so we neither request them nor expect they must be allowed.
         if (options.credentialsRequested == ClientDidNotRequestCredentials)
             options.allowCredentials = DoNotAllowStoredCredentials;
     }
     return true;
 }
 
 } // namespace blink