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

chrome/browser/chromeos/gdata/gdata_file_system.cc

Index: chrome/browser/chromeos/gdata/gdata_file_system.cc
diff --git a/chrome/browser/chromeos/gdata/gdata_file_system.cc b/chrome/browser/chromeos/gdata/gdata_file_system.cc
index e8e111c08ff3dc5ed77a8176a8d3d4367aa2bda0..377d9e744f0deca0fe04edeba0e0bbdfd4f065d4 100644
--- a/chrome/browser/chromeos/gdata/gdata_file_system.cc
+++ b/chrome/browser/chromeos/gdata/gdata_file_system.cc
@@ -915,7 +915,8 @@ void GDataFileSystem::OnGetAccountMetadata(
     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()) {