Have HashMap<KeyType, AtomicString>::get() return a const reference

Source/platform/network/ResourceRequest.h

 /*
  * Copyright (C) 2003, 2006 Apple Computer, Inc.  All rights reserved.
  * Copyright (C) 2006 Samuel Weinig <sam.weinig@gmail.com>
  * Copyright (C) 2009, 2012 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 104 matching lines @@
     double timeoutInterval() const; // May return 0 when using platform default.
     void setTimeoutInterval(double timeoutInterval);
 
     const KURL& firstPartyForCookies() const;
     void setFirstPartyForCookies(const KURL& firstPartyForCookies);
 
     const AtomicString& httpMethod() const;
     void setHTTPMethod(const AtomicString&);
 
     const HTTPHeaderMap& httpHeaderFields() const;
-    AtomicString httpHeaderField(const AtomicString& name) const;
+    const AtomicString& httpHeaderField(const AtomicString& name) const;
     const AtomicString& httpHeaderField(const char* name) const;
     void setHTTPHeaderField(const AtomicString& name, const AtomicString& value);
     void setHTTPHeaderField(const char* name, const AtomicString& value);
     void addHTTPHeaderField(const AtomicString& name, const AtomicString& value);
     void addHTTPHeaderFields(const HTTPHeaderMap& headerFields);
     void clearHTTPHeaderField(const AtomicString& name);
 
     void clearHTTPAuthorization();
 
-    AtomicString httpContentType() const { return httpHeaderField("Content-Type");  }
+    const AtomicString& httpContentType() const { return httpHeaderField("Content-Type");  }
     void setHTTPContentType(const AtomicString& httpContentType) { setHTTPHeaderField("Content-Type", httpContentType); }
     void clearHTTPContentType();
 
-    AtomicString httpReferrer() const { return httpHeaderField("Referer"); }
+    const AtomicString& httpReferrer() const { return httpHeaderField("Referer"); }
     void setHTTPReferrer(const AtomicString& httpReferrer) { setHTTPHeaderField("Referer", httpReferrer); }
     void clearHTTPReferrer();
 
-    AtomicString httpOrigin() const { return httpHeaderField("Origin"); }
+    const AtomicString& httpOrigin() const { return httpHeaderField("Origin"); }
     void setHTTPOrigin(const AtomicString& httpOrigin) { setHTTPHeaderField("Origin", httpOrigin); }
     void clearHTTPOrigin();
 
-    AtomicString httpUserAgent() const { return httpHeaderField("User-Agent"); }
+    const AtomicString& httpUserAgent() const { return httpHeaderField("User-Agent"); }
     void setHTTPUserAgent(const AtomicString& httpUserAgent) { setHTTPHeaderField("User-Agent", httpUserAgent); }
     void clearHTTPUserAgent();
 
-    AtomicString httpAccept() const { return httpHeaderField("Accept"); }
+    const AtomicString& httpAccept() const { return httpHeaderField("Accept"); }
     void setHTTPAccept(const AtomicString& httpAccept) { setHTTPHeaderField("Accept", httpAccept); }
     void clearHTTPAccept();
 
     FormData* httpBody() const;
     void setHTTPBody(PassRefPtr<FormData> httpBody);
 
     bool allowCookies() const;
     void setAllowCookies(bool allowCookies);
 
     ResourceLoadPriority priority() const;
@@ skipping 103 matching lines @@
     int m_requestorProcessID;
     int m_appCacheHostID;
     ResourceRequest::TargetType m_targetType;
 };
 
 unsigned initializeMaximumHTTPConnectionCountPerHost();
 
 } // namespace WebCore
 
 #endif // ResourceRequest_h