Use Drive v2 API: enable behind --enable-drive-api flag

chrome/browser/chromeos/gdata/gdata_file_system.cc

 // 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.
 
 #include "chrome/browser/chromeos/gdata/gdata_file_system.h"
 
 #include <set>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 897 matching lines @@
                        true,  /* should_fetch_multiple_feeds */
                        search_file_path,
                        std::string() /* no search query */,
                        std::string() /* no directory resource ID */,
                        callback,
                        base::Bind(&GDataFileSystem::OnFeedFromServerLoaded,
                                   ui_weak_ptr_));
     return;
   }
 
-  webapps_registry_->UpdateFromFeed(account_metadata.get());
+  if (!gdata::util::IsDriveV2ApiEnabled())

[satorux1, 2012/07/12 07:49:06]

does this mean the webapps registry does not work if if drive v2 is enabled?
please add some comment.

[kochi, 2012/07/13 10:33:52]

I intend to separate a new DriveFileSystem class and
will not add code such as this.

[satorux1, 2012/07/14 07:15:34]

DriveFileSystem will likely share a lot of code with the existing
GDataFileSystem implementation. However, using inheritance to share
implementation tends to result in hard-to-read code, hence should usually be
avoided. If we are to introduce DriveFileSystem, I guess we'd need to move out
lots of code from GDataFileSystem...

Just adding some gdata::util::IsDriveV2ApiEnabled() calls in the existing code
maybe be simpler. Just for a food for thoughts.

+    webapps_registry_->UpdateFromFeed(account_metadata.get());
 
   bool changes_detected = true;
   if (local_changestamp >= account_metadata->largest_changestamp()) {
     if (local_changestamp > account_metadata->largest_changestamp()) {
       LOG(WARNING) << "Cached client feed is fresher than server, client = "
                    << local_changestamp
                    << ", server = "
                    << account_metadata->largest_changestamp();
     }
     root_->set_origin(initial_origin);
@@ skipping 2991 matching lines @@
   // must go through here. Removes the |file_path| from the remembered set so
   // that subsequent operations can open the file again.
   open_files_.erase(file_path);
 
   // Then invokes the user-supplied callback function.
   if (!callback.is_null())
     callback.Run(result);
 }
 
 }  // namespace gdata