libaddressinput - one less copy when downloading data

third_party/libaddressinput/chromium/chrome_downloader_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef THIRD_PARTY_LIBADDRESSINPUT_CHROMIUM_CHROME_DOWNLOADER_IMPL_H_
 #define THIRD_PARTY_LIBADDRESSINPUT_CHROMIUM_CHROME_DOWNLOADER_IMPL_H_
 
 #include <map>
 #include <string>
 
@@ skipping 18 matching lines @@
 
   // ::i18n::addressinput::Downloader:
   virtual void Download(const std::string& url,
                         scoped_ptr<Callback> downloaded) OVERRIDE;
 
   // net::URLFetcherDelegate:
   virtual void OnURLFetchComplete(const net::URLFetcher* source) OVERRIDE;
 
  private:
   struct Request {
-    Request(const std::string& url, scoped_ptr<Callback> callback);
+    Request(const std::string& url,
+            scoped_ptr<net::URLFetcher> fetcher,
+            scoped_ptr<Callback> callback);
 
     std::string url;
+    // The data that's received.
+    std::string data;
+    // The object that manages retrieving the data.
+    scoped_ptr<net::URLFetcher> fetcher;
     scoped_ptr<Callback> callback;
   };
 
   net::URLRequestContextGetter* const getter_;  // weak
 
-  // Maps from active url fetcher to request metadata. Both the key and value
-  // are owned.
+  // Maps from active url fetcher to request metadata. The value is owned.
   std::map<const net::URLFetcher*, Request*> requests_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeDownloaderImpl);
 };
 
 }  // namespace autofill
 
 #endif  // THIRD_PARTY_LIBADDRESSINPUT_CHROMIUM_CHROME_DOWNLOADER_IMPL_H_