Only schedule a warmup when a user has the app launcher enabled

Only schedule a warmup when a user has the app launcher enabled.

This avoids a possibly janky delayed UI task for users that don't use
the app launcher.

After this, a user enabling the app list for the first time won't have a
warmed-up UI but that shouldn't matter because the education page
doesn't try to show it, and ShowForAppInstall() will warm it up.

BUG=431326, 292969
Committed: https://crrev.com/9bbd8ea8ee4a3816ac513ae5fb46f66d19d44f4c
Cr-Commit-Position: refs/heads/master@{#322451}

[tapted, 2015-03-25 20:57:06]

tapted@chromium.org changed reviewers:
+ benwells@chromium.org

[tapted, 2015-03-25 21:39:27]

Hi ben, wdyt?

[benwells, 2015-03-25 22:19:49]

lgtm

https://codereview.chromium.org/1031223002/diff/20001/chrome/browser/ui/views...
File chrome/browser/ui/views/app_list/win/app_list_service_win.cc (right):

https://codereview.chromium.org/1031223002/diff/20001/chrome/browser/ui/views...
chrome/browser/ui/views/app_list/win/app_list_service_win.cc:348: // it's not
already enabled.
Nit: might be worth explaining somewhere why you both to do it in canary.

[benwells, 2015-03-25 22:19:49]

lgtm

lgtm

https://codereview.chromium.org/1031223002/diff/20001/chrome/browser/ui/views...
File chrome/browser/ui/views/app_list/win/app_list_service_win.cc (right):

https://codereview.chromium.org/1031223002/diff/20001/chrome/browser/ui/views...
chrome/browser/ui/views/app_list/win/app_list_service_win.cc:348: // it's not
already enabled.
Nit: might be worth explaining somewhere why you both to do it in canary.

[tapted, 2015-03-26 18:42:22]

I've noted calamity's patch in https://codereview.chromium.org/1016503006/ as
well (for checking 28-day actives). It doesn't conflict with this - it hooks in
later, and in the posted task rather than on the startup path. I guess this is
technically redundant, but since it's on the startup path I think it still has
merit. Maybe there will be an opportunity to check what impact this simple
approach has on any UMA.

https://codereview.chromium.org/1031223002/diff/20001/chrome/browser/ui/views...
File chrome/browser/ui/views/app_list/win/app_list_service_win.cc (right):

https://codereview.chromium.org/1031223002/diff/20001/chrome/browser/ui/views...
chrome/browser/ui/views/app_list/win/app_list_service_win.cc:348: // it's not
already enabled.
On 2015/03/25 22:19:49, benwells wrote:
> Nit: might be worth explaining somewhere why you both to do it in canary.

Done.

[tapted, 2015-03-26 18:43:26]

The CQ bit was checked by tapted@chromium.org

[tapted, 2015-03-26 18:43:27]

The patchset sent to the CQ was uploaded after l-g-t-m from
benwells@chromium.org
Link to the patchset: https://codereview.chromium.org/1031223002/#ps40001
(title: "update comment")

[commit-bot: I haz the power, 2015-03-26 18:44:00]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1031223002/40001

[commit-bot: I haz the power, 2015-03-26 19:51:22]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-03-26 19:52:49]

Patchset 3 (id:??) landed as
https://crrev.com/9bbd8ea8ee4a3816ac513ae5fb46f66d19d44f4c
Cr-Commit-Position: refs/heads/master@{#322451}