Update the Drive state in Files app when the refresh token is fetched.

Update the Drive state in Files app when the refresh token is fetched.

Before, we were not notifying Files app about such fact, so it was still
thinking that Drive is not available, and showing the banner.

TEST=Tested manually when logging to an empty profile.
BUG=461247
Committed: https://crrev.com/eaffcdbc813caebe3160789ed9ecc503b5276926
Cr-Commit-Position: refs/heads/master@{#317995}

[mtomasz, 2015-02-25 05:37:10]

mtomasz@chromium.org changed reviewers:
+ hirono@chromium.org

[mtomasz, 2015-02-25 05:37:17]

@hirono: PTAL. Thanks.

[hirono, 2015-02-25 05:46:12]

lgtm!

[mtomasz, 2015-02-25 05:50:41]

The CQ bit was checked by mtomasz@chromium.org

[commit-bot: I haz the power, 2015-02-25 05:52:01]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/953273002/1

[commit-bot: I haz the power, 2015-02-25 06:13:10]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-25 06:13:36]

Patchset 1 (id:??) landed as
https://crrev.com/eaffcdbc813caebe3160789ed9ecc503b5276926
Cr-Commit-Position: refs/heads/master@{#317995}