DevTools: remove test script-window-close-breakpoint.html

The patch kills invalid test script-window-close-breakpoint.html.
The test itself expoits an old bug crbug.com/6773 and closes
main window instead of a programmatically created one. This
causes the layout test driver to crash on the following
test as there's no window to navigate.

BUG=423364

Review URL: https://codereview.chromium.org/656083002

git-svn-id: svn://svn.chromium.org/blink/trunk@183747 bbb929c8-8fbe-4397-9dbb-9b2b20218538