drive/syncFS: Switch to ID based download URL.

chrome/browser/sync_file_system/drive_backend/api_util.cc

 // Copyright 2013 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 "chrome/browser/sync_file_system/drive_backend/api_util.h"
 
 #include <algorithm>
 #include <functional>
 #include <sstream>
 #include <string>
@@ skipping 469 matching lines @@
       base::Bind(&APIUtil::DidGetResourceList, AsWeakPtr(), callback));
 }
 
 void APIUtil::DownloadFile(const std::string& resource_id,
                            const std::string& local_file_md5,
                            const base::FilePath& local_file_path,
                            const DownloadFileCallback& callback) {
   DCHECK(CalledOnValidThread());
   DVLOG(2) << "Downloading file [" << resource_id << "]";
 
   drive_service_->GetResourceEntry(

[tzik, 2013/07/02 12:34:27]

If |local_file_md5| is empty, we might able to skip this GetResourceEntry call
and can call DriveServiceInterface::DownloadFile directly.

[kinaba, 2013/07/02 13:15:09]

yeah, the same goes for Drive side as well.
Can I try that in the next separate patch?
I feel the current patch is already big enough.

[kinaba, 2013/07/03 02:18:56]

Fm, I also thought this is possible, but it turned out to be difficult.
APIUtil::DownloadFile calls back with (new) md5, size, and modification time
that can only be retrieved from GetResourceEntry.

I'm now thinking keeping this part as is. What do you think?

[tzik, 2013/07/03 02:40:42]

Hmm, right it's not trivial.
OK, please leave it as is.

       resource_id,
       base::Bind(&APIUtil::DidGetResourceEntry,
                  AsWeakPtr(),
                  base::Bind(&APIUtil::DownloadFileInternal,
                             AsWeakPtr(),
                             local_file_md5,
                             local_file_path,
                             callback)));
 }
 
@@ skipping 215 matching lines @@
   // If local file and remote file are same, cancel the download.
   if (local_file_md5 == entry->file_md5()) {
     callback.Run(google_apis::HTTP_NOT_MODIFIED,
                  local_file_md5,
                  entry->file_size(),
                  entry->updated_time());
     return;
   }
 
   DVLOG(2) << "Downloading file: " << entry->resource_id();
-  const GURL& download_url = entry->download_url();
+  const std::string& resource_id = entry->resource_id();
   drive_service_->DownloadFile(local_file_path,
-                               download_url,
+                               resource_id,
                                base::Bind(&APIUtil::DidDownloadFile,
                                           AsWeakPtr(),
                                           base::Passed(&entry),
                                           callback),
                                google_apis::GetContentCallback(),
                                google_apis::ProgressCallback());
 }
 
 void APIUtil::DidDownloadFile(scoped_ptr<google_apis::ResourceEntry> entry,
                               const DownloadFileCallback& callback,
@@ skipping 337 matching lines @@
 }
 
 std::string APIUtil::GetRootResourceId() const {
   if (IsDriveAPIDisabled())
     return drive_service_->GetRootResourceId();
   return root_resource_id_;
 }
 
 }  // namespace drive_backend
 }  // namespace sync_file_system