Revert of Omnibox: Combine Two Input Type Enums into One

Revert of Omnibox: Combine Two Input Type Enums into One (https://codereview.chromium.org/319523005/)

Reason for revert:
Broke the build on http://build.chromium.org/p/chromium.chrome/builders/Google%20Chrome%20Mac

Original issue's description:
> Omnibox: Combine Two Input Type Enums into One
> 
> There are two input type enums:
> * one in the autocomplete code
> * one in the metrics code that's used for UMA logging;
>   this one is meant to remain stable
> 
> As part of fixing the linked bug, I created
> https://codereview.chromium.org/314773002/
> whch needed an input type enum, one which would remain stable.
> It didn't necessarily have to be the metrics enum.
> 
> After discussion with the UMA folks (who deal with how to handle
> stable enum problems all the time), we reached the conclusion
> that we should have one stable enum and use it everywhere.  That's
> the cleanest answer.
> 
> This single enum has to live in the metrics directory because metrics
> is a component.
> 
> This change combines the two existing enums into one, putting the
> new enum in a new file in the metrics directory.  The reason for
> a new file is so we can include it without include the whole
> OmniboxEventProto or any other metrics code.
> 
> The main files to review are autocomplete_input.h and *.proto.
> All other changes are a mechanical result of the changes in
> those three files.
> 
> The internal proto change has been submitted.
> 
> TBR=stevenjb
> for the trivial change to chrome/browser/ui/app_list/search/omnibox_provider.cc
> that removes an unnecessary include
> 
> BUG=284781
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275696

TBR=pkasting@chromium.org,isherman@chromium.org,mpearson@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=284781
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=275706

[dcheng, 2014-06-07 23:17:50]

Created Revert of Omnibox: Combine Two Input Type Enums into One

[commit-bot: I haz the power, 2014-06-07 23:18:27]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dcheng@chromium.org/320713002/1

[commit-bot: I haz the power, 2014-06-07 23:19:17]

Change committed as 275706