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

Source/core/xml/XMLHttpRequest.cpp

 /*
  *  Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005-2007 Alexey Proskuryakov <ap@webkit.org>
  *  Copyright (C) 2007, 2008 Julien Chaffraix <jchaffraix@webkit.org>
  *  Copyright (C) 2008, 2011 Google Inc. All rights reserved.
  *  Copyright (C) 2012 Intel Corporation
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 607 matching lines @@
 void XMLHttpRequest::send(Document* document, ExceptionState& exceptionState)
 {
     WTF_LOG(Network, "XMLHttpRequest %p send() Document %p", this, document);
 
     ASSERT(document);
 
     if (!initSend(exceptionState))
         return;
 
     if (areMethodAndURLValidForSend()) {
-        String contentType = getRequestHeader("Content-Type");
-        if (contentType.isEmpty()) {
+        if (getRequestHeader("Content-Type").isEmpty()) {
             // FIXME: this should include the charset used for encoding.
             setRequestHeaderInternal("Content-Type", "application/xml");
         }
 
         // FIXME: According to XMLHttpRequest Level 2, this should use the Document.innerHTML algorithm
         // from the HTML5 specification to serialize the document.
         String body = createMarkup(document);
 
         // FIXME: This should use value of document.inputEncoding to determine the encoding to use.
         m_requestEntityBody = FormData::create(UTF8Encoding().encode(body, WTF::EntitiesForUnencodables));
@@ skipping 29 matching lines @@
 }
 
 void XMLHttpRequest::send(Blob* body, ExceptionState& exceptionState)
 {
     WTF_LOG(Network, "XMLHttpRequest %p send() Blob '%s'", this, body->uuid().utf8().data());
 
     if (!initSend(exceptionState))
         return;
 
     if (areMethodAndURLValidForSend()) {
-        const String& contentType = getRequestHeader("Content-Type");
-        if (contentType.isEmpty()) {
+        if (getRequestHeader("Content-Type").isEmpty()) {
             const String& blobType = body->type();
             if (!blobType.isEmpty() && isValidContentType(blobType))
                 setRequestHeaderInternal("Content-Type", AtomicString(blobType));
             else {
                 // From FileAPI spec, whenever media type cannot be determined, empty string must be returned.
                 setRequestHeaderInternal("Content-Type", "");
             }
         }
 
         // FIXME: add support for uploading bundles.
@@ skipping 387 matching lines @@
     setRequestHeaderInternal(name, value);
 }
 
 void XMLHttpRequest::setRequestHeaderInternal(const AtomicString& name, const AtomicString& value)
 {
     HTTPHeaderMap::AddResult result = m_requestHeaders.add(name, value);
     if (!result.isNewEntry)
         result.iterator->value = result.iterator->value + ", " + value;
 }
 
-AtomicString XMLHttpRequest::getRequestHeader(const AtomicString& name) const
+const AtomicString& XMLHttpRequest::getRequestHeader(const AtomicString& name) const
 {
     return m_requestHeaders.get(name);
 }
 
 String XMLHttpRequest::getAllResponseHeaders(ExceptionState& exceptionState) const
 {
     if (m_state < HEADERS_RECEIVED || m_error)
         return "";
 
     StringBuilder stringBuilder;
@@ skipping 18 matching lines @@
         stringBuilder.append(':');
         stringBuilder.append(' ');
         stringBuilder.append(it->value);
         stringBuilder.append('\r');
         stringBuilder.append('\n');
     }
 
     return stringBuilder.toString();
 }
 
-AtomicString XMLHttpRequest::getResponseHeader(const AtomicString& name, ExceptionState& exceptionState) const
+const AtomicString& XMLHttpRequest::getResponseHeader(const AtomicString& name, ExceptionState& exceptionState) const
 {
     if (m_state < HEADERS_RECEIVED || m_error)
         return nullAtom;
 
     // See comment in getAllResponseHeaders above.
     if (isSetCookieHeader(name) && !securityOrigin()->canLoadLocalResources()) {
         logConsoleError(executionContext(), "Refused to get unsafe header \"" + name + "\"");
         return nullAtom;
     }
 
@@ skipping 255 matching lines @@
 {
     return EventTargetNames::XMLHttpRequest;
 }
 
 ExecutionContext* XMLHttpRequest::executionContext() const
 {
     return ActiveDOMObject::executionContext();
 }
 
 } // namespace WebCore