Revert of [ServiceWorker] Don't allow registration of the ServiceWorker scope outside the script directory. (patchset #4 id:70001 of https://codereview.chromium.org/672383003/)

Reason for revert:
This patch seems to have broken the following two browser_tests on all platforms, as can be seen on the non-layout bots on the Blink waterfall. We won't be able to roll Blink in Chromium until this is resolved.

PushMessagingBrowserTest.RegisterFailureNoPermission
PushMessagingBrowserTest.RegisterSuccess

Example output:
http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests%20%28dbg%29/builds/4400/steps/browser_tests/logs/RegisterSuccess

[INFO:CONSOLE(7)] "SecurityError - The scope must be under the directory of the script URL.", source: https://127.0.0.1:39935/files/push_messaging/test.html (7)
../../chrome/browser/services/gcm/push_messaging_browsertest.cc:142: Failure
Value of: register_worker_result
  Actual: "SecurityError - The scope must be under the directory of the script URL."
Expected: "ok"

Original issue's description:
> [ServiceWorker] Don't allow registration of the ServiceWorker scope outside the script directory.
> 
> As per discussion on https://github.com/slightlyoff/ServiceWorker/issues/468
> 
> BUG=423983
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=184336

TBR=falken@chromium.org,horo@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=423983

Review URL: https://codereview.chromium.org/672353003

git-svn-id: svn://svn.chromium.org/blink/trunk@184364 bbb929c8-8fbe-4397-9dbb-9b2b20218538