Update XHR resource leak expectations.

The leaks were fixed at [1].

1: http://src.chromium.org/viewvc/blink/trunk/Source/core/fetch/ResourceLoader.cpp?r1=180749&r2=180748&pathrev=180749

BUG=402743
NOTRY=true

Review URL: https://codereview.chromium.org/501883002

git-svn-id: svn://svn.chromium.org/blink/trunk@180880 bbb929c8-8fbe-4397-9dbb-9b2b20218538