Unify include structure in //components/sync_driver unittests

Unify include structure in //components/sync_driver unittests

This CL hoists the includes of the files being tested to the top of the
unittest file in all unittests under //components/sync_driver.

Committed: https://crrev.com/e772a83b47267033c022f6c10bf64eb04f057806
Cr-Commit-Position: refs/heads/master@{#355124}

[blundell, 2015-10-20 09:39:04]

blundell@chromium.org changed reviewers:
+ zea@chromium.org

[blundell, 2015-10-20 09:39:04]

I realized it wouldn't actually be a great idea to do a sweep in
//chrome/browser/sync right now as there are so many in-flight componentization
CLs. Instead, we can fix those ones up as we componentize them.

[Nicolas Zea, 2015-10-20 18:10:16]

LGTM, thanks!

[blundell, 2015-10-20 18:30:45]

The CQ bit was checked by blundell@chromium.org

[commit-bot: I haz the power, 2015-10-20 18:31:20]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1414233002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1414233002/1

[commit-bot: I haz the power, 2015-10-20 19:06:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-10-20 19:07:21]

Patchset 1 (id:??) landed as
https://crrev.com/e772a83b47267033c022f6c10bf64eb04f057806
Cr-Commit-Position: refs/heads/master@{#355124}