Rename cookie names in WebSocket cookie tests

- remove unnecessary WK- prefix
- Names of cookies generated by helper scripts should be independent of
  the user (test case) so that they can be shared among multiple test
  cases. We replace "pass" and "fail" with phrases that describe the
  attributes set to the cookies

BUG=none
R=yhirano

Review-Url: https://codereview.chromium.org/2123743002
Cr-Commit-Position: refs/heads/master@{#403855}
10 files changed