ServiceWorker: Abort register() and getRegistration() on non-http(s) page

Currently the ServiceWorker backend does not support register() and
getRegistration() calls on non-HTTP(s) page (eg, "file://"). Such calls
trigger a renderer crash because SWProviderHost does not have a valid
document URL and treats a request as a bad message.

This patch makes SWContainer abort such calls before sending an IPC message.


BUG=432048
TEST=run-webkit-tests fast/serviceworker/access-container-on-local-file.html

Review URL: https://codereview.chromium.org/722583002

git-svn-id: svn://svn.chromium.org/blink/trunk@185210 bbb929c8-8fbe-4397-9dbb-9b2b20218538