Change ScriptContextTest.GetEffectiveDocumentURL to use FrameLoadWaiter and re-enable the test.

Change ScriptContextTest.GetEffectiveDocumentURL to use FrameLoadWaiter and re-enable the test.

FrameLoadWaiter relies on DidFinishLoad, which correctly takes into account sub-frame loads as well, so this should fix the test flakiness.

BUG=391894
Committed: https://crrev.com/cbb4b862bb3ad12a1e98c0fd0cd65a01defb5055
Cr-Commit-Position: refs/heads/master@{#293415}

[Marijn Kruisselbrink, 2014-09-03 19:52:08]

mek@chromium.org changed reviewers:
+ dcheng@chromium.org, jam@chromium.org

[Marijn Kruisselbrink, 2014-09-03 19:52:09]

Needing a content/ OWNER reviewer because this moves FrameLoadWaiter from
content/test to content/public/test to make it accessible for extensions/ code.

[jam, 2014-09-04 22:25:12]

lgtm

[Marijn Kruisselbrink, 2014-09-04 22:42:26]

The CQ bit was checked by mek@chromium.org

[commit-bot: I haz the power, 2014-09-04 22:43:43]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/mek@chromium.org/537023002/40001

[commit-bot: I haz the power, 2014-09-05 03:09:32]

Committed patchset #3 (id:40001) as 6a7368c7dff004b2525187e5b5824f16f69a0cb3

[commit-bot: I haz the power, 2014-09-10 03:36:05]

Patchset 3 (id:??) landed as
https://crrev.com/cbb4b862bb3ad12a1e98c0fd0cd65a01defb5055
Cr-Commit-Position: refs/heads/master@{#293415}