ServiceWorker CacheID update

ServiceWorker CacheID update

Previous design:
1. The renderer needed all references to the same ServiceWorekrCache* to have the same CacheID.
2. The renderer would only send an IPC that a CacheID was deleted when the last reference to the CacheID was deleted in javascript.

After https://codereview.chromium.org/474593002/ and https://codereview.chromium.org/433793002/:
1. The renderer doesn't need all references to the same ServiceWorkerCache* to have the same CacheID.
2. The renderer will send an IPC that a CacheID is deleted after each javascript cache object is deleted.

To address the change on the browser side, simply make a new CacheID for every call to GetCache and CreateCache and delete its corresponding refptr when the CacheID is dropped.

BUG=392621
Committed: https://crrev.com/821ee0da2cd4a3203d30f82c15f34829d0e182c0
Cr-Commit-Position: refs/heads/master@{#296390}

[jkarlin, 2014-09-23 14:19:13]

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

[jkarlin, 2014-09-23 14:19:14]

michaeln@chromium.org: Please review changes in all

horo@chromium.org: Please review changes in all

Thanks!

[jkarlin, 2014-09-23 14:19:29]

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

[jkarlin, 2014-09-23 14:19:38]

On 2014/09/23 14:19:14, jkarlin wrote:
> mailto:michaeln@chromium.org: Please review changes in all
> 
> mailto:horo@chromium.org: Please review changes in all
> 
> Thanks!

gavinp: FYI

[gavinp, 2014-09-23 16:11:43]

lgtm

[horo, 2014-09-24 06:25:25]

lgtm

[jkarlin, 2014-09-24 11:05:25]

The CQ bit was checked by jkarlin@chromium.org

[commit-bot: I haz the power, 2014-09-24 11:06:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/599473002/1

[commit-bot: I haz the power, 2014-09-24 11:56:34]

Committed patchset #1 (id:1) as 8c05b7b4ba990746072abac36324d930106816fe

[commit-bot: I haz the power, 2014-09-24 11:57:25]

Patchset 1 (id:??) landed as
https://crrev.com/821ee0da2cd4a3203d30f82c15f34829d0e182c0
Cr-Commit-Position: refs/heads/master@{#296390}