Only support seeking file streams from the beginning of the file.

content/browser/android/url_request_content_job.cc

 // Copyright (c) 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.
 
 #include "content/browser/android/url_request_content_job.h"
 
 #include "base/android/content_uri_utils.h"
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 159 matching lines @@
     NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED,
                                      net::ERR_REQUEST_RANGE_NOT_SATISFIABLE));
     return;
   }
 
   remaining_bytes_ = byte_range_.last_byte_position() -
                      byte_range_.first_byte_position() + 1;
   DCHECK_GE(remaining_bytes_, 0);
 
   if (remaining_bytes_ > 0 && byte_range_.first_byte_position() != 0) {
-    int rv = stream_->Seek(base::File::FROM_BEGIN,
-                           byte_range_.first_byte_position(),
+    int rv = stream_->Seek(byte_range_.first_byte_position(),
                            base::Bind(&URLRequestContentJob::DidSeek,
                                       weak_ptr_factory_.GetWeakPtr()));
     if (rv != net::ERR_IO_PENDING) {
       // stream_->Seek() failed, so pass an intentionally erroneous value
       // into DidSeek().
       DidSeek(-1);
     }
   } else {
     // We didn't need to call stream_->Seek() at all, so we pass to DidSeek()
     // the value that would mean seek success. This way we skip the code
@@ skipping 27 matching lines @@
   if (result == 0) {
     NotifyDone(net::URLRequestStatus());
   } else if (result < 0) {
     NotifyDone(net::URLRequestStatus(net::URLRequestStatus::FAILED, result));
   }
 
   NotifyReadComplete(result);
 }
 
 }  // namespace content