Add callback for upload progress in Drive service and operation layer.

Add callback for upload progress in Drive service and operation layer.

This is a preparation for moving the progress report creation task
from OperationRegistry to DriveScheduler. For that purpose we need to
wire the progress information to upper layer.

The current patch only adds the new callback parameter.
Actual implementation will come later in separate patches.

BUG=128079
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=193092

[kinaba, 2013-04-09 06:34:41]

ptal

[hidehiko, 2013-04-09 06:46:32]

On 2013/04/09 06:34:41, kinaba wrote:
> ptal

LGTM.
Hope we won't conflict...

[commit-bot: I haz the power, 2013-04-09 07:52:10]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/kinaba@chromium.org/13927002/2021

[commit-bot: I haz the power, 2013-04-09 14:05:37]

Change committed as 193092