[GCM] Adding GCMAccountMapper tests

[GCM] Adding GCMAccountMapper tests

Patch updated after a revert. Original patch:
https://codereview.chromium.org/544363002/

1) When the status is ADDING (adding message is sent), the token is refreshed.
2) When the status is REMOVING (removing message is sent), the token is added
again.
3) updating multiple account mappings

BUG=374969
R=jianli@chromium.org

Committed: https://crrev.com/93f486469d03bf0333e92b2c69e471af4e17b787
Cr-Commit-Position: refs/heads/master@{#294259}

[fgorski, 2014-09-09 21:29:04]

Jian, PTAL, patchset 1 is the original, patchset 2 is the fix.

[jianli, 2014-09-10 21:07:55]

https://codereview.chromium.org/560563003/diff/20001/components/gcm_driver/gc...
File components/gcm_driver/gcm_account_mapper_unittest.cc (right):

https://codereview.chromium.org/560563003/diff/20001/components/gcm_driver/gc...
components/gcm_driver/gcm_account_mapper_unittest.cc:758: actual_iter =
mappings.begin();
Could you please introduce a helper function to capture all these similar codes?

[fgorski, 2014-09-10 21:30:19]

PTAL

https://codereview.chromium.org/560563003/diff/20001/components/gcm_driver/gc...
File components/gcm_driver/gcm_account_mapper_unittest.cc (right):

https://codereview.chromium.org/560563003/diff/20001/components/gcm_driver/gc...
components/gcm_driver/gcm_account_mapper_unittest.cc:758: actual_iter =
mappings.begin();
On 2014/09/10 21:07:55, jianli wrote:
> Could you please introduce a helper function to capture all these similar
codes?

Done.

[jianli, 2014-09-10 21:34:05]

lgtm

[fgorski, 2014-09-10 21:34:33]

The CQ bit was checked by fgorski@chromium.org

[commit-bot: I haz the power, 2014-09-10 21:37:29]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/fgorski@chromium.org/560563003/40001

[commit-bot: I haz the power, 2014-09-10 23:38:51]

Committed patchset #3 (id:40001) as 4a0128671a416d2a8a5e419607abce272dae6e23

[commit-bot: I haz the power, 2014-09-10 23:41:56]

Patchset 3 (id:??) landed as
https://crrev.com/93f486469d03bf0333e92b2c69e471af4e17b787
Cr-Commit-Position: refs/heads/master@{#294259}