[ServiceWorkerCache Cleanup] Make the state of the cache backend explicit

[ServiceWorkerCache] Make the state of the cache backend explicit

The ServiceWorkerCache's backend transitions from uninitialized, to
open, to closed.  Make that explicit in code by adding a state
variable instead of checking the state of the initialized_ and
backend_ member variables.

BUG=430884
Committed: https://crrev.com/7fbcce797ed32cf1d653ca5e4bf1dfad4cd7fc46
Cr-Commit-Position: refs/heads/master@{#303115}

[jkarlin, 2014-11-06 16:35:11]

jkarlin@chromium.org changed reviewers:
+ michaeln@chromium.org

[jkarlin, 2014-11-06 16:35:11]

Thanks michaeln.  Hopefully this makes the code clearer.

[michaeln, 2014-11-06 22:01:09]

lgtm!

[jkarlin, 2014-11-06 22:16:23]

On 2014/11/06 22:01:09, michaeln wrote:
> lgtm!

Thanks!

[jkarlin, 2014-11-06 22:16:26]

The CQ bit was checked by jkarlin@chromium.org

[commit-bot: I haz the power, 2014-11-06 22:18:08]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/701403002/20001

[commit-bot: I haz the power, 2014-11-06 23:05:15]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-11-06 23:05:55]

Patchset 2 (id:??) landed as
https://crrev.com/7fbcce797ed32cf1d653ca5e4bf1dfad4cd7fc46
Cr-Commit-Position: refs/heads/master@{#303115}

[falken, 2014-11-07 05:03:21]

falken@chromium.org changed reviewers:
+ falken@chromium.org

[falken, 2014-11-07 05:03:21]

This seems to have broken http/tests/serviceworker/cache-match.html:
https://code.google.com/p/chromium/issues/detail?id=431163

https://codereview.chromium.org/701403002/diff/20001/content/browser/service_...
File content/browser/service_worker/service_worker_cache.h (right):

https://codereview.chromium.org/701403002/diff/20001/content/browser/service_...
content/browser/service_worker/service_worker_cache.h:115: BackendUninitialized,
 // No backend, create backend on first operation.
Style nit: chromium enums are SNAKE_CASE

[jkarlin, 2014-11-07 12:46:45]

A revert of this CL (patchset #2 id:20001) has been created in
https://codereview.chromium.org/709003003/ by jkarlin@chromium.org.

The reason for reverting is: There is a bad DCHECK causing layout tests to fail.
 Reverting and fixing later so that I can turn the tests back on asap as this
patch is non-essential and it's branch day.

BUG=431163.

[jkarlin, 2014-11-07 18:55:57]

https://codereview.chromium.org/701403002/diff/20001/content/browser/service_...
File content/browser/service_worker/service_worker_cache.h (right):

https://codereview.chromium.org/701403002/diff/20001/content/browser/service_...
content/browser/service_worker/service_worker_cache.h:115: BackendUninitialized,
 // No backend, create backend on first operation.
On 2014/11/07 05:03:21, falken wrote:
> Style nit: chromium enums are SNAKE_CASE

Thanks! Done in https://codereview.chromium.org/692993005/