Add UKM API GetNewSourceID()

Add UKM API GetNewSourceID()

This CL adds a new UKM API GetNewSourceID(). So different subsystems
can use the same API to get new source ID to avoid collision.

BUG=678682
Review-Url: https://codereview.chromium.org/2727013002
Cr-Commit-Position: refs/heads/master@{#454168}
Committed: https://chromium.googlesource.com/chromium/src/+/d433dd5d64e4b2ffc352906dbf72bdd6d2df1fe8

[Zhen Wang, 2017-03-01 22:38:32]

Description was changed from

==========
Add UKM API GetNewSourceID()

BUG=678682
==========

to

==========
Add UKM API GetNewSourceID()

This CL adds a new UKM API GetNewSourceID(). So different subsystems
can use the same API to get new source ID to avoid collision.

BUG=678682
==========

[Zhen Wang, 2017-03-01 22:44:23]

zhenw@chromium.org changed reviewers:
+ bmcquade@chromium.org, holte@google.com, rkaplow@chromium.org

[Zhen Wang, 2017-03-01 22:44:24]

I am adding this new UKM API so that the translate folks and page_load_metrics
folks do not need to worry about source ID collision.

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service.h
File components/ukm/ukm_service.h (right):

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service....
components/ukm/ukm_service.h:53: static int32_t GetNewSourceID();
We probably do not need static here. The benefit of using static is that even if
we have more than one UkmService instance, we still get unique new ID. But that
may not ever happen. Let me know if anyone would prefer to remove static here.

[Zhen Wang, 2017-03-01 22:44:37]

The CQ bit was checked by zhenw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-01 22:45:15]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Bryan McQuade, 2017-03-01 22:46:35]

LGTM, thanks!

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service.h
File components/ukm/ukm_service.h (right):

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service....
components/ukm/ukm_service.h:52: // Get the new source ID.
let's expand this comment to say something like 'Each returned ID is guaranteed
to be unique for the duration of a browser session.'

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service....
components/ukm/ukm_service.h:53: static int32_t GetNewSourceID();
On 2017/03/01 at 22:44:24, Zhen Wang wrote:
> We probably do not need static here. The benefit of using static is that even
if we have more than one UkmService instance, we still get unique new ID. But
that may not ever happen. Let me know if anyone would prefer to remove static
here.

I think static is totally fine - I'd use static here as well.

[Zhen Wang, 2017-03-01 22:51:42]

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service.h
File components/ukm/ukm_service.h (right):

https://codereview.chromium.org/2727013002/diff/1/components/ukm/ukm_service....
components/ukm/ukm_service.h:52: // Get the new source ID.
On 2017/03/01 22:46:35, Bryan McQuade wrote:
> let's expand this comment to say something like 'Each returned ID is
guaranteed
> to be unique for the duration of a browser session.'

Done.

[Zhen Wang, 2017-03-01 22:51:52]

The CQ bit was checked by zhenw@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2017-03-01 22:52:23]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[rkaplow, 2017-03-01 23:09:51]

lgtm

[Zhen Wang, 2017-03-01 23:10:20]

The CQ bit was unchecked by zhenw@chromium.org

[Zhen Wang, 2017-03-01 23:10:24]

The CQ bit was checked by zhenw@chromium.org

[Zhen Wang, 2017-03-01 23:10:25]

The patchset sent to the CQ was uploaded after l-g-t-m from
bmcquade@chromium.org
Link to the patchset: https://codereview.chromium.org/2727013002/#ps20001
(title: "fix comment")

[commit-bot: I haz the power, 2017-03-01 23:10:52]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Bryan McQuade, 2017-03-02 02:04:50]

The CQ bit was unchecked by bmcquade@chromium.org

[Bryan McQuade, 2017-03-02 02:07:32]

On 2017/03/01 at 23:10:52, commit-bot wrote:
> CQ is trying da patch. Follow status at
>  
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

the mac_chromium_rel_ng bot seems to have gotten hung, so i'm trying to start a
new tryjob for that bot in hopes that it succeeds. will re-enable commit for
this change if it succeeds.

[Zhen Wang, 2017-03-02 03:07:47]

Thanks Bryan! mac_chromium_rel_ng succeed. will commit now.

[Zhen Wang, 2017-03-02 03:07:53]

The CQ bit was checked by zhenw@chromium.org

[commit-bot: I haz the power, 2017-03-02 03:08:34]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2017-03-02 03:43:49]

CQ is committing da patch.

Bot data: {"patchset_id": 20001, "attempt_start_ts": 1488424073818460,
"parent_rev": "589a2e258a84a834d5a446760dd45cd3ac90ce35", "commit_rev":
"d433dd5d64e4b2ffc352906dbf72bdd6d2df1fe8"}

[commit-bot: I haz the power, 2017-03-02 03:44:25]

Description was changed from

==========
Add UKM API GetNewSourceID()

This CL adds a new UKM API GetNewSourceID(). So different subsystems
can use the same API to get new source ID to avoid collision.

BUG=678682
==========

to

==========
Add UKM API GetNewSourceID()

This CL adds a new UKM API GetNewSourceID(). So different subsystems
can use the same API to get new source ID to avoid collision.

BUG=678682

Review-Url: https://codereview.chromium.org/2727013002
Cr-Commit-Position: refs/heads/master@{#454168}
Committed:
https://chromium.googlesource.com/chromium/src/+/d433dd5d64e4b2ffc352906dbf72...
==========

[commit-bot: I haz the power, 2017-03-02 03:44:33]

Committed patchset #2 (id:20001) as
https://chromium.googlesource.com/chromium/src/+/d433dd5d64e4b2ffc352906dbf72...