Use a Finch Experiment to control the Browser Blacklist

Use a Finch Experiment to control the Browser Blacklist

Also increase the states stored in the register to prevent
the setup code from running multiple times per version if
it fails to start one time.

Also, this uses RegQueryValueEx and RegSetValueEx
instead of RegSetKeyValue and RegGetValue since 
they aren't available on XP.

TBR=sky@chromium.org
BUG=329023
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=244517

[csharp, 2014-01-10 16:14:14]

Patch 1 is just https://codereview.chromium.org/120963002/.
Patch 2 replaces the functions that aren't available on XP.

[csharp, 2014-01-10 21:36:06]

I'd forgotten to fix the unit tests, they should now be fixed (testing now).

[Cait (Slow), 2014-01-10 21:54:07]

Regkey handling changes lgtm

[Cait (Slow), 2014-01-10 21:54:10]

Regkey handling changes lgtm

[robertshield, 2014-01-11 01:40:14]

lgtm

[commit-bot: I haz the power, 2014-01-13 13:54:28]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/csharp@chromium.org/133923002/200002

[commit-bot: I haz the power, 2014-01-13 16:57:07]

Change committed as 244517