[Telemetry] Remove session_restore.{cold|warm}.startup_urls (previously disabled)

Remove disabled tests session_restore.cold.startup_urls and session_restore.warm.startup_urls.

These are adding to the maintenance burden. If they need to be brought back to life, the measurement will need a substitute for CanRunForPage because that method is going away. https://codereview.chromium.org/808893002/

The CL that disabled the tests: https://codereview.chromium.org/738663002

BUG=389142, 405386, 440101
Committed: https://crrev.com/ce9f11ad6c803515f5bc170629a2f795bd275d43
Cr-Commit-Position: refs/heads/master@{#308737}

[slamm, 2014-12-17 00:24:49]

Patchset #1 (id:1) has been deleted

[slamm, 2014-12-17 00:32:20]

slamm@chromium.org changed reviewers:
+ annie.sullivan@gmail.com, tonyg@chromium.org

[slamm, 2014-12-17 00:32:21]

Annie, these are the tests I asked about removing earlier today.

[slamm, 2014-12-17 00:37:35]

slamm@chromium.org changed reviewers:
+ sullivan@chromium.org
- annie.sullivan@gmail.com

[slamm, 2014-12-17 00:38:00]

On 2014/12/17 00:32:21, slamm wrote:
> Annie, these are the tests I asked about removing earlier today.

Update Annie's email address.

[chrishenry, 2014-12-17 00:42:32]

chrishenry@google.com changed reviewers:
+ chrishenry@google.com

[chrishenry, 2014-12-17 00:42:32]

lgtm, thanks!

[sullivan, 2014-12-17 00:49:07]

lgtm

[slamm, 2014-12-17 01:06:00]

The CQ bit was checked by slamm@chromium.org

[commit-bot: I haz the power, 2014-12-17 01:07:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/809653004/20001

[commit-bot: I haz the power, 2014-12-17 03:06:29]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2014-12-17 03:07:23]

Patchset 1 (id:??) landed as
https://crrev.com/ce9f11ad6c803515f5bc170629a2f795bd275d43
Cr-Commit-Position: refs/heads/master@{#308737}