Remove deprecated FieldTrialHelper.

Remove deprecated FieldTrialHelper.

The downstream dependencies in Chrome for Android have been
updated to use org.chromium.base.FieldTrialList, so the old
code can be removed.

BUG=378035
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=282251

[nyquist, 2014-07-09 20:46:02]

Could you expand the description a bit to say why this now can be removed? (i.e.
saying that the calling code now has been updated to call the new API at
FooBar).
Also, has that happened? I couldn't seem to find a CL that changed the other
code.

[maxbogue, 2014-07-09 21:15:07]

On 2014/07/09 20:46:02, nyquist wrote:
> Could you expand the description a bit to say why this now can be removed?
(i.e.
> saying that the calling code now has been updated to call the new API at
> FooBar).
> Also, has that happened? I couldn't seem to find a CL that changed the other
> code.

Done, and I PM'd you a link to the relevant Clank CL.

[nyquist, 2014-07-09 21:46:46]

lgtm

[maxbogue, 2014-07-09 21:52:54]

The CQ bit was checked by maxbogue@chromium.org

[commit-bot: I haz the power, 2014-07-09 21:55:28]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/maxbogue@chromium.org/378403002/1

[commit-bot: I haz the power, 2014-07-10 04:26:25]

Change committed as 282251