Remove startup_url from PageSet, we can now only specify startup_url on a Page.

Remove startup_url from PageSet, we can now only specify startup_url on a Page.
Also make startup_url immutable.

BUG=439512
Committed: https://crrev.com/5a1a8edb923692c2075810955c867a4f941fb78e
Cr-Commit-Position: refs/heads/master@{#307116}

[chrishenry, 2014-12-05 20:56:36]

Patchset #1 (id:1) has been deleted

[chrishenry, 2014-12-05 21:39:53]

chrishenry@google.com changed reviewers:
+ achuith@chromium.org, nednguyen@google.com, slamm@chromium.org

[chrishenry, 2014-12-05 21:39:54]

I'm a little surprised that there isn't more pages that use startup_url. Am I
missing anything obvious?

[nednguyen, 2014-12-05 21:45:09]

On 2014/12/05 21:39:54, chrishenry wrote:
> I'm a little surprised that there isn't more pages that use startup_url. Am I
> missing anything obvious?

If you already grep and that's what you fine, then it's probably it.

[nednguyen, 2014-12-05 21:46:23]

lgtm

[chrishenry, 2014-12-05 21:51:35]

On 2014/12/05 21:45:09, nednguyen wrote:
> On 2014/12/05 21:39:54, chrishenry wrote:
> > I'm a little surprised that there isn't more pages that use startup_url. Am
I
> > missing anything obvious?
> 
> If you already grep and that's what you fine, then it's probably it.

Yep, grep the usual suspect (telemetry|perf|gpu).

[slamm, 2014-12-05 22:24:29]

lgtm

https://codereview.chromium.org/782033002/diff/20001/tools/telemetry/telemetr...
File tools/telemetry/telemetry/unittest_util/page_set_smoke_test.py (right):

https://codereview.chromium.org/782033002/diff/20001/tools/telemetry/telemetr...
tools/telemetry/telemetry/unittest_util/page_set_smoke_test.py:124: msg=('page
%s \'s startup_url field must have type string'
BTW, self.assertIsInstance is available.

[chrishenry, 2014-12-05 22:45:48]

The CQ bit was checked by chrishenry@google.com

[commit-bot: I haz the power, 2014-12-05 22:46:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/782033002/20001

[commit-bot: I haz the power, 2014-12-05 23:43:33]

Committed patchset #1 (id:20001)

[commit-bot: I haz the power, 2014-12-05 23:45:08]

Patchset 1 (id:??) landed as
https://crrev.com/5a1a8edb923692c2075810955c867a4f941fb78e
Cr-Commit-Position: refs/heads/master@{#307116}