[ServiceWorker] Remove the test for the rejected result of FetchEvent from fetch-event.html

[ServiceWorker] Remove the test for the rejected result of FetchEvent from fetch-event.html

We don't have the way to observe the network error using <iframe>.
So this change removes the rejecting test from fetch-event.html

I will introduce the reject test using XMLHttpRequest later. (step 3)

Step1: this patch
  [ServiceWorker] Remove the test for the rejected result of FetchEvent from fetch-event.html
  https://codereview.chromium.org/588993002/
Step2: [ServiceWorker] Treat the rejected result of onFetch as a Network Error.
  https://codereview.chromium.org/590043002/
Step3: [ServiceWorker] Add test for the rejected result of FetchEvent using XHR.
 https://codereview.chromium.org/588093003/

BUG=411173
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=182401

[horo, 2014-09-22 05:29:20]

horo@chromium.org changed reviewers:
+ yhirano@chromium.org

[horo, 2014-09-22 05:29:20]

yhirano@
Could you please review?

[yhirano, 2014-09-22 07:43:02]

lgtm

[horo, 2014-09-22 07:58:07]

The CQ bit was checked by horo@chromium.org

[commit-bot: I haz the power, 2014-09-22 07:59:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/588993002/1

[commit-bot: I haz the power, 2014-09-22 09:05:43]

Committed patchset #1 (id:1) as 182401