Deflake 'http/tests/security/isolatedWorld/bypass-main-world-csp-for-inline-script.html'.

I accidentally left a debug 'setTimeout()' call in this test, which forced
completion after two seconds. That was fairly silly, and caused some flake,
as the test would prematurely exit if it was taking too long.

This is bad enough, but it turns out that exiting early caused the
'alert()' usage in the test would also leak into the next test, causing an
assertion in DocumentLoader because the modal dialog defered the next test's
load.

This patch should fix both issues.

BUG=249021
R=jochen@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19506006

git-svn-id: svn://svn.chromium.org/blink/trunk@154396 bbb929c8-8fbe-4397-9dbb-9b2b20218538