Support range uploading of a file.

net/url_request/url_fetcher.h

Index: net/url_request/url_fetcher.h
diff --git a/net/url_request/url_fetcher.h b/net/url_request/url_fetcher.h
index 9d2be1d80b51e61c6f0b4246a628232319ac02c7..326c764494172f76a87e578d7af6615d286ec57d 100644
--- a/net/url_request/url_fetcher.h
+++ b/net/url_request/url_fetcher.h
@@ -141,6 +141,16 @@ class NET_EXPORT URLFetcher {
       const base::FilePath& file_path,
       scoped_refptr<base::TaskRunner> file_task_runner) = 0;
 
+  // Sets data only needed by POSTs as same as SetUploadFilePath().
+  // The only difference is that this method takes the |range_offset| and
+  // |range_length| to upload a part of the file at |file_path|.
+  virtual void SetUploadFilePathWithRange(
+      const std::string& upload_content_type,
+      const base::FilePath& file_path,
+      uint64 range_offset,
+      uint64 range_length,

[hashimoto, 2013/04/30 10:27:36]

Instead of adding a new method, can we add these range parameters to
SetUploadFilePath?
The method is used by only one user, two_phase_uploader.cc.

[hidehiko, 2013/04/30 11:30:14]

We can, but should we do that?
I'm thinking that setting (0, kuint64max) at client side (to upload whole the
file) may not good stuff because it's just the implementation details. WDYT?

[hashimoto, 2013/05/01 06:39:21]

I don't think we should maintain two unpopular methods at the same time which
has only one user for each.

Historically, SetUploadFilePath was introduced because the attempt to add more
general SetUploadDataStream method had failed due to the problem around retry.
(http://crbug.com/169551)
I think setting kuint64max is not beautiful but acceptable because
SetUploadFilePath is meant to be an alternative for manual setup of
UploadFileElementReader.

[hidehiko, 2013/05/01 13:51:49]

Ok. Done.

+      scoped_refptr<base::TaskRunner> file_task_runner) = 0;
+
   // Indicates that the POST data is sent via chunked transfer encoding.
   // This may only be called before calling Start().
   // Use AppendChunkToUpload() to give the data chunks after calling Start().