Clean up OffTheRecordProfileImplTest unit test

Clean up OffTheRecordProfileImplTest unit test

The previous version of this test could create up to 4 TestingProfiles:
1. TestingProfile from BrowserWithTestWindowTest::CreateProfile
2. TestingProfileWithHostZoomMap in the test body
3. An incognito version created by (2) via GetOffTheRecordProfile().
4. An incognito version created in the test body

Also the master/incognito relationships between these profiles are unclear.

Reduce this to the 2 needed instances:
1. TestingProfileWithHostZoomMap owned by BrowserWithTestWindowTest
2. An incognito version in the test body

BUG=395329
TEST=unit_tests OffTheRecordProfileImplTest.*

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=284590

[James Cook, 2014-07-19 03:32:06]

erg, PTAL.

[Elliot Glaysher, 2014-07-21 21:07:22]

lgtm

[James Cook, 2014-07-21 22:45:46]

The CQ bit was checked by jamescook@chromium.org

[commit-bot: I haz the power, 2014-07-21 22:47:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jamescook@chromium.org/403103003/20001

[commit-bot: I haz the power, 2014-07-22 02:05:27]

Change committed as 284590