Reduce the copying of string data between C++ and javascript in proxy_resolver_v8.cc.

net/proxy/proxy_script_fetcher.h

-// Copyright (c) 2008 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.
+// Copyright (c) 2010 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.
 
 // ProxyScriptFetcher is an async interface for fetching a proxy auto config
 // script. It is specific to fetching a PAC script; enforces timeout, max-size,
 // status code.
 
 #ifndef NET_PROXY_PROXY_SCRIPT_FETCHER_H_
 #define NET_PROXY_PROXY_SCRIPT_FETCHER_H_
 
-#include <string>
-
+#include "base/string16.h"
 #include "net/base/completion_callback.h"
 #include "testing/gtest/include/gtest/gtest_prod.h"
 
 class GURL;
 class URLRequestContext;
 
 namespace net {
 
 class ProxyScriptFetcher {
  public:
   // Destruction should cancel any outstanding requests.
   virtual ~ProxyScriptFetcher() {}
 
   // Downloads the given PAC URL, and invokes |callback| on completion.
-  // On success |callback| is executed with a result code of OK, and a
-  // string of the response bytes (as UTF8). On failure, the result bytes is
+  // On success |callback| is executed with a result code of OK, |*utf16_text|
+  // is filled with the response. On failure, the result text is
   // an empty string, and the result code is a network error. Some special
   // network errors that may occur are:
   //
   //    ERR_TIMED_OUT         -- the fetch took too long to complete.
   //    ERR_FILE_TOO_BIG      -- the response's body was too large.
   //    ERR_PAC_STATUS_NOT_OK -- non-200 HTTP status code.
   //    ERR_NOT_IMPLEMENTED   -- the response required authentication.
   //
   // If the request is cancelled (either using the "Cancel()" method or by
   // deleting |this|), then no callback is invoked.
   //
   // Only one fetch is allowed to be outstanding at a time.
-  virtual int Fetch(const GURL& url, std::string* utf8_bytes,
+  virtual int Fetch(const GURL& url, string16* utf16_text,
                     CompletionCallback* callback) = 0;
 
   // Aborts the in-progress fetch (if any).
   virtual void Cancel() = 0;
 
   // Returns the request context that this fetcher uses to issue downloads,
   // or NULL.
   virtual URLRequestContext* GetRequestContext() { return NULL; }
 
   // Create a ProxyScriptFetcher that uses |url_request_context|.
@@ skipping 11 matching lines @@
   static int SetTimeoutConstraintForUnittest(int timeout_ms);
 
   // Sets the maximum response size for a fetch to |size_bytes|. Returns the
   // previous bound.
   static size_t SetSizeConstraintForUnittest(size_t size_bytes);
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SCRIPT_FETCHER_H_