Remove TestRunner_resources target.

After https://codereview.chromium.org/120683005/, TestRunner_resources
will not be used anymore and thus can be removed from Blink. We also
need to remove it, at least from all.gyp, to avoid the "multiple rules"
warning on ninja.

BUG=331303
TEST=None
R=jochen@chromium.org,abarth@chromium.org

Review URL: https://codereview.chromium.org/132663004

git-svn-id: svn://svn.chromium.org/blink/trunk@164850 bbb929c8-8fbe-4397-9dbb-9b2b20218538