Move Cache Storage API implementation to modules/cachestorage

Move Cache Storage API implementation to modules/cachestorage

Since it's no longer limited to Service Worker context, give it a
module of its very own.

Add jkarlin to OWNERS

BUG=439389
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=193152

[jsbell, 2015-04-01 18:56:10]

This is dependent on https://codereview.chromium.org/1057443002/ or another fix
for http://crbug.com/472273

[jsbell, 2015-04-03 19:34:27]

jsbell@chromium.org changed reviewers:
+ dmurph@chromium.org

[jsbell, 2015-04-03 19:34:27]

dmurph: Should I wait on the devtools changes or go ahead and get this landed?

[dmurph, 2015-04-03 20:37:50]

On 2015/04/03 at 19:34:27, jsbell wrote:
> dmurph: Should I wait on the devtools changes or go ahead and get this landed?

You can land it

[dmurph, 2015-04-03 21:16:11]

lgtm

[jsbell, 2015-04-03 21:29:51]

The CQ bit was checked by jsbell@chromium.org

[commit-bot: I haz the power, 2015-04-03 21:30:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1055543004/20001

[commit-bot: I haz the power, 2015-04-04 00:32:36]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=193152