Convert tests to use GetURL(host, path) instead of redirector.

Convert tests to use GetURL(host, path) instead of redirector.

As discovered by japhet@, if we navigate cross-site in a browser test using the '/cross-site/' redirector syntax, the initial URL is relative to the embedded_test_server, which happens to also be the SiteInstance of the top-level page. This causes an extra process swap, which is unnecessary and can create unexpected effects in the test. I've added GetURL(hostname, path) method to EmbeddedTestServer to give us the proper URL directly without following a redirect path and this CL updates the tests to use this new method.

BUG=418236
Committed: https://crrev.com/30374c75c1736fe2a476382edcadd68fc5ddc0d0
Cr-Commit-Position: refs/heads/master@{#302126}

[nasko, 2014-10-30 17:35:51]

nasko@chromium.org changed reviewers:
+ creis@chromium.org, japhet@chromium.org

[nasko, 2014-10-30 17:35:51]

Hey Charlie,
Can you review this CL for me? I've added Nate as FYI.
Thanks!
Nasko

[Charlie Reis, 2014-10-30 17:39:33]

I like it-- it's a bit cleaner as well.  LGTM.

[nasko, 2014-10-30 17:41:50]

The CQ bit was checked by nasko@chromium.org

[commit-bot: I haz the power, 2014-10-30 17:42:07]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/688363002/1

[commit-bot: I haz the power, 2014-10-30 19:18:44]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-10-30 19:19:24]

Patchset 1 (id:??) landed as
https://crrev.com/30374c75c1736fe2a476382edcadd68fc5ddc0d0
Cr-Commit-Position: refs/heads/master@{#302126}