Allow URLFetcher to be used from sequenced tasks.

net/url_request/url_fetcher.h

 // Copyright (c) 2012 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 NET_URL_REQUEST_URL_FETCHER_H_
 #define NET_URL_REQUEST_URL_FETCHER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 49 matching lines @@
 //   fetcher.reset();
 //
 // The object you supply as a delegate must inherit from URLFetcherDelegate.
 // When the fetch is completed, OnURLFetchComplete() will be called with a
 // pointer to the URLFetcher. From that point until the original URLFetcher
 // instance is destroyed, you may use accessor methods to see the result of the
 // fetch. You should copy these objects if you need them to live longer than
 // the URLFetcher instance. If the URLFetcher instance is destroyed before the
 // callback happens, the fetch will be canceled and no callback will occur.
 //
-// You may create the URLFetcher instance on any thread; OnURLFetchComplete()
-// will be called back on the same thread you use to create the instance.
+// You may create the URLFetcher instance on any sequence; OnURLFetchComplete()
+// will be called back on the same sequence you use to create the instance.
 //
 //
 // NOTE: By default URLFetcher requests are NOT intercepted, except when
 // interception is explicitly enabled in tests.
 class NET_EXPORT URLFetcher {
  public:
   // Imposible http response code. Used to signal that no http response code
   // was received.
   enum ResponseCode {
     RESPONSE_CODE_INVALID = -1
@@ skipping 247 matching lines @@
   // be removed once the URLFetcher is destroyed.  User should not take
   // ownership more than once, or call this method after taking ownership.
   virtual bool GetResponseAsFilePath(
       bool take_ownership,
       base::FilePath* out_response_path) const = 0;
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_FETCHER_H_