Revert of [ServiceWorker] Make Response class better conformance with the spec.

Revert of [ServiceWorker] Make Response class better conformance with the spec. (https://codereview.chromium.org/373613004/)

Reason for revert:
Broke content_browsertests

http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests/builds/37860

ServiceWorkerVersionBrowserTest.FetchEvent_Response
ServiceWorkerBrowserTest.Reload


Original issue's description:
> [ServiceWorker] Make Response class better conformance with the spec.
> 
> In current implementation Response class only supports status, statusText, and headers attributes.
> This change introduce type, url attributes and change the class of headers attribute from HeaderMap to Headers and make all attributes readonly.
> And also this change implements the logic which is defined in the spec.
> 
> http://fetch.spec.whatwg.org/#response-class 
> http://fetch.spec.whatwg.org/#response
> 
> 
> This cl depends on http://crrev.com/329853012 and http://crrev.com/370733002
> 
> BUG=373120
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177793

TBR=falken@chromium.org,haraken@chromium.org,tkent@chromium.org,horo@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=373120
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=177803

[Yuta Kitamura, 2014-07-10 05:12:39]

Created Revert of [ServiceWorker] Make Response class better conformance with
the spec.

[commit-bot: I haz the power, 2014-07-10 05:13:07]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/yutak@chromium.org/383653002/1

[commit-bot: I haz the power, 2014-07-10 05:13:53]

Change committed as 177803