Cache Storage: Remove unused Service/Embedder Worker plumbing

Cache Storage: Remove unused Service/Embedder Worker plumbing

Follow up to https://codereview.chromium.org/1029423004 that cleans up
the now-unused plumbing for the Cache Storage API routed through
Service Worker and Embedded Worker classes. Service Workers and other
contexts can access the API via the embedder API.

BUG=439389
R=kinuko@chromium.org,michaeln@chromium.org

Committed: https://crrev.com/c328fc4acba1b6b7760f4d81deed79b1d0d04c50
Cr-Commit-Position: refs/heads/master@{#322386}

[jsbell, 2015-03-25 17:32:10]

kinuko@, michaeln@ - please take a look?

This can't land until http://crrev.com/1031063002 and
http://crrev.com/1029423004 are in. It doesn't block any other work but its
easy.

[michaeln, 2015-03-25 19:04:29]

(+0 lines, -27 lines) lgtm!

[kinuko, 2015-03-25 23:53:02]

lgtm yay~

[jsbell, 2015-03-26 14:15:02]

The CQ bit was checked by jsbell@chromium.org

[commit-bot: I haz the power, 2015-03-26 14:15:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1022703003/1

[commit-bot: I haz the power, 2015-03-26 15:14:54]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-03-26 15:15:23]

Patchset 1 (id:??) landed as
https://crrev.com/c328fc4acba1b6b7760f4d81deed79b1d0d04c50
Cr-Commit-Position: refs/heads/master@{#322386}