Replace GetAccountMetadata by GetAboutResource in sync_file_system.

Replace GetAccountMetadata by GetAboutResource in sync_file_system.

GetAboutResource is supported by both GData WAPI and Drive API v2, while
GetAccountMetadata is now only supported by GData WAPI.
To prepare Drive API v2 migration, replace GetAccountMetadata by
GetAboutResource.
Note that GetAboutResource doesn't include installed third party application
info, but fortunately it is not used in sync file system so we don't need
to take care about it.

BUG=174237
TEST=Ran unit_tests


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=186194

[hidehiko, 2013-03-04 14:24:28]

Thank you for your review in advance,
- hidehiko

[kinaba, 2013-03-04 22:50:37]

lgtm, but defer the final decision naturally to tzik@

[tzik, 2013-03-05 07:15:45]

lgtm

[hidehiko, 2013-03-05 12:45:44]

On 2013/03/05 07:15:45, tzik wrote:
> lgtm

Kazuhiro, Taiju, thank you for your review!
Ryo, would you mind to have a double check just in case?

Thanks,
- hidehiko

[hashimoto, 2013-03-05 14:05:12]

lgtm

[commit-bot: I haz the power, 2013-03-05 14:05:49]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/hidehiko@chromium.org/12385081/2001

[commit-bot: I haz the power, 2013-03-05 17:20:35]

Change committed as 186194