Unlaunch the HIDDEN mode.

Unlaunch the HIDDEN mode.

Lots of changes:
1. Unlaunch the HIDDEN mode, by putting it back under the UMA guard. This is
   based on what was decided at Chrome Product Strategy.
2. Eliminate --preload-instant-search, making preloading the default. I think
   preloading has been around long enough and stable enough that we can do so.
3. Restructure the field trial header, removing convenience methods and letting
   clients explicitly refer to the modes. I found having to recall what exactly
   "IsHiddenExperiment()" constituted (HIDDEN? SUGGEST? both?) was a drag.
4. Make SILENT the default, as per Search team's request. So, any time a user
   in one of the other modes doesn't satisfy the requirements (such as having
   UMA or suggest enabled), they'll fall through to SILENT. The only exception
   is if they are in CONTROL.
5. Remove INACTIVE. It's the same as CONTROL anyway.
6. Remove the 'ix' param to stop leaking UMA opt-in state to non-Google sites.
7. Rename "Group" to "Mode" to more accurately reflect the fact that this is
   the current mode of operation, despite whatever group the user fell into.

BUG=none
TEST=none


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=135298

[sreeram, 2012-05-03 21:06:21]

Please review. It probably would be better to split some things up into separate
CLs, but there's really not much behaviour / functionality change here (apart
from the preload thing and unlaunching HIDDEN).

@cpu for chrome/app/generated_resources.grd
@jhawkins for chrome/browser/ui/webui/options2/browser_options_handler2.cc
@sky for everything else.

https://chromiumcodereview.appspot.com/10353017/diff/1/chrome/browser/instant...
File chrome/browser/instant/instant_controller.cc (right):

https://chromiumcodereview.appspot.com/10353017/diff/1/chrome/browser/instant...
chrome/browser/instant/instant_controller.cc:452: InstantFieldTrial::SILENT) {
@sky: Should this instead be:
if (InstantFieldTrial::GetMode(...) == InstantFieldTrial::INSTANT) {

I.e., send the focus for only the visible INSTANT mode, since neither HIDDEN nor
SUGGEST show a preview (just like SILENT). However, I'm not sure why this was
added, so please advise.

[sreeram, 2012-05-03 21:07:16]

Please review. It probably would be better to split some things up into separate
CLs, but there's really not much behaviour / functionality change here (apart
from the preload thing and unlaunching HIDDEN).

@cpu for chrome/app/generated_resources.grd
@jhawkins for chrome/browser/ui/webui/options2/browser_options_handler2.cc
@sky for everything else.

[James Hawkins, 2012-05-03 21:08:00]

webui LGTM

[sky, 2012-05-03 21:22:09]

LGTM with change you suggested

https://chromiumcodereview.appspot.com/10353017/diff/1/chrome/browser/instant...
File chrome/browser/instant/instant_controller.cc (right):

https://chromiumcodereview.appspot.com/10353017/diff/1/chrome/browser/instant...
chrome/browser/instant/instant_controller.cc:452: InstantFieldTrial::SILENT) {
On 2012/05/03 21:06:21, sreeram wrote:
> @sky: Should this instead be:
> if (InstantFieldTrial::GetMode(...) == InstantFieldTrial::INSTANT) {
> 
> I.e., send the focus for only the visible INSTANT mode, since neither HIDDEN
nor
> SUGGEST show a preview (just like SILENT). However, I'm not sure why this was
> added, so please advise.

Yes, this should only matter for visible INSTANT mode, so your suggestion seems
right. The instant tests running on chromeos exercise this code, so as long as
those tests still pass you're good.

[cpu_(ooo_6.6-7.5), 2012-05-03 21:23:59]

grt LGTM

[commit-bot: I haz the power, 2012-05-04 03:20:07]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/sreeram@chromium.org/10353017/9001

[commit-bot: I haz the power, 2012-05-04 04:34:09]

Change committed as 135298