Keep workerStart timing info over request job restarts

Keep workerStart timing info over request job restarts

In ServiceWorkerControlleeRequestHandler, job_ may be created multiple
times, or cleared (for example, when the request falls back to network).
In those cases, the workerStart timing info should hold the first time
SW started for the request.

This patch makes ServiceWorkerControlleeRequestHandler remember the
workerStart time from the first job.

BUG=465640
TEST=Will be added in https://codereview.chromium.org/1152673004/

Committed: https://crrev.com/9c6eec3e56dd43ec87bc486e17f6b9dfcb957af0
Cr-Commit-Position: refs/heads/master@{#331766}

[Kunihiko Sakamoto, 2015-05-28 04:40:27]

ksakamoto@chromium.org changed reviewers:
+ horo@chromium.org

[horo, 2015-05-28 10:11:37]

lgtm with nit

https://codereview.chromium.org/1160883004/diff/1/content/browser/service_wor...
File content/browser/service_worker/service_worker_controllee_request_handler.cc
(right):

https://codereview.chromium.org/1160883004/diff/1/content/browser/service_wor...
content/browser/service_worker/service_worker_controllee_request_handler.cc:68:
// save worker-start time of the first job.
nit s/s/S

[Kunihiko Sakamoto, 2015-05-28 10:21:19]

https://codereview.chromium.org/1160883004/diff/1/content/browser/service_wor...
File content/browser/service_worker/service_worker_controllee_request_handler.cc
(right):

https://codereview.chromium.org/1160883004/diff/1/content/browser/service_wor...
content/browser/service_worker/service_worker_controllee_request_handler.cc:68:
// save worker-start time of the first job.
On 2015/05/28 10:11:37, horo wrote:
> nit s/s/S

Done.

[Kunihiko Sakamoto, 2015-05-28 10:21:26]

The CQ bit was checked by ksakamoto@chromium.org

[Kunihiko Sakamoto, 2015-05-28 10:21:26]

The patchset sent to the CQ was uploaded after l-g-t-m from horo@chromium.org
Link to the patchset: https://codereview.chromium.org/1160883004/#ps20001
(title: " ")

[commit-bot: I haz the power, 2015-05-28 10:21:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1160883004/20001

[commit-bot: I haz the power, 2015-05-28 11:47:59]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-05-28 11:48:53]

Patchset 2 (id:??) landed as
https://crrev.com/9c6eec3e56dd43ec87bc486e17f6b9dfcb957af0
Cr-Commit-Position: refs/heads/master@{#331766}