Revert 182604 "Introducing the WebServiceWorkerCache."

> Introducing the WebServiceWorkerCache.
> 
> This CL provides the new WebServiceWorkerCache object, which connects the
> ServiceWorker Cache between blink and content. There's two notable exceptions
> in the implementation; the various Cache.add() and Cache.addAll() methods are
> not implemented (they should do fetches in blink and provide the responses to
> this API through the batch call), and Response bodies via blobs is not implemented.
> 
> R=dominicc@chromium.org,falken@chromium.org,jkarlin@chromium.org
> BUG=399178
> 
> Review URL: https://codereview.chromium.org/433793002

TBR=gavinp@chromium.org

Review URL: https://codereview.chromium.org/602723002

git-svn-id: svn://svn.chromium.org/blink/trunk@182607 bbb929c8-8fbe-4397-9dbb-9b2b20218538