Added metrics to track the time between task switches done via Alt+Tab and Alt+Shift+Tab.

Added metrics to track the time between task switches done via Alt+Tab and Alt+Shift+Tab.

TEST=TaskSwitchMetricsRecorderTest.VerifyTaskSwitchesForWindowCycleControllerAreRecorded

BUG=478946
Committed: https://crrev.com/c343193276d07ebb2b184a790e5c0f60d2f98cd3
Cr-Commit-Position: refs/heads/master@{#330099}

[bruthig, 2015-05-13 19:46:03]

bruthig@chromium.org changed reviewers:
+ asvitkine@chromium.org, oshima@chromium.org, rkaplow@chromium.org,
tdanderson@chromium.org

[bruthig, 2015-05-13 19:46:03]

NOTE: This review is based on the CL in-flight here:
https://codereview.chromium.org/1133123003/

asvitkine@/rkaplow@: Please review changes in
 - tools/metrics/histograms/histograms.xml

oshima@: Please review changes in
 - ash/*

tdanderson@: Please review changes from a feature accuracy perspective.

[bruthig, 2015-05-13 21:47:43]

On 2015/05/13 19:46:03, bruthig wrote:
> NOTE: This review is based on the CL in-flight here:
> https://codereview.chromium.org/1133123003/
> 
> asvitkine@/rkaplow@: Please review changes in
>  - tools/metrics/histograms/histograms.xml
> 
> oshima@: Please review changes in
>  - ash/*
> 
> tdanderson@: Please review changes from a feature accuracy perspective.

Please hold off on this review.  I have to make some changes.

[bruthig, 2015-05-14 00:25:46]

NOTE: This review is based on the CL in-flight here:
https://codereview.chromium.org/1133123003/

This is now ready for review.

asvitkine@/rkaplow@: Please review changes in
 - tools/metrics/histograms/histograms.xml

oshima@: Please review changes in
 - ash/*

tdanderson@: Please review changes from a feature accuracy perspective.

[oshima, 2015-05-14 17:12:36]

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
File ash/wm/window_cycle_controller.cc (right):

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
ash/wm/window_cycle_controller.cc:91: active_window_before_window_cycle_ =
GetActiveWindow(window_list);
doesn't GetActiveWindow work here?

[bruthig, 2015-05-14 17:49:45]

NOTE: This review is based on the CL in-flight here:
https://codereview.chromium.org/1133123003/

I've responded to oshima@'s comments.

asvitkine@/rkaplow@: Please review changes in
 - tools/metrics/histograms/histograms.xml

oshima@: Please review changes in
 - ash/*

tdanderson@: Please review changes from a feature accuracy perspective.

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
File ash/wm/window_cycle_controller.cc (right):

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
ash/wm/window_cycle_controller.cc:91: active_window_before_window_cycle_ =
GetActiveWindow(window_list);
On 2015/05/14 17:12:36, oshima wrote:
> doesn't GetActiveWindow work here?

Summary of discussion offline.

wm::GetActiveWindow() can return transient windows for things like the status
tray which are not included in the definition of a "Task".  So this is
intentionally comparing the last active window that is also choose-able via
Alt+Tab.

Will leave it as-is.

[oshima, 2015-05-14 18:13:00]

lgtm

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
File ash/wm/window_cycle_controller.cc (right):

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
ash/wm/window_cycle_controller.cc:91: active_window_before_window_cycle_ =
GetActiveWindow(window_list);
On 2015/05/14 17:49:44, bruthig wrote:
> On 2015/05/14 17:12:36, oshima wrote:
> > doesn't GetActiveWindow work here?
> 
> Summary of discussion offline.
> 
> wm::GetActiveWindow() can return transient windows for things like the status
> tray which are not included in the definition of a "Task".  So this is
> intentionally comparing the last active window that is also choose-able via
> Alt+Tab.
> 
> Will leave it as-is.

Acknowledged.

[Alexei Svitkine (slow), 2015-05-14 20:42:14]

lgtm

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
File ash/wm/window_cycle_controller.cc (right):

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
ash/wm/window_cycle_controller.cc:24: return window_list.size() > 0 ?
window_list[0] : nullptr;
Nit: .size() > 0 -> !.empty()

[bruthig, 2015-05-14 22:06:40]

Fixed asvitkine@'s nit in patch set 7.

No need to re-review.

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
File ash/wm/window_cycle_controller.cc (right):

https://codereview.chromium.org/1126333005/diff/120001/ash/wm/window_cycle_co...
ash/wm/window_cycle_controller.cc:24: return window_list.size() > 0 ?
window_list[0] : nullptr;
On 2015/05/14 20:42:14, Alexei Svitkine wrote:
> Nit: .size() > 0 -> !.empty()

Done.

[bruthig, 2015-05-14 22:06:46]

The CQ bit was checked by bruthig@chromium.org

[bruthig, 2015-05-14 22:06:46]

The patchset sent to the CQ was uploaded after l-g-t-m from
asvitkine@chromium.org, oshima@chromium.org
Link to the patchset: https://codereview.chromium.org/1126333005/#ps140001
(title: "Changed "window_list.size() > 0" to "window.empty()".")

[commit-bot: I haz the power, 2015-05-14 22:07:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1126333005/140001

[commit-bot: I haz the power, 2015-05-14 22:17:45]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-05-14 22:17:46]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[bruthig, 2015-05-15 15:36:39]

The CQ bit was checked by bruthig@chromium.org

[commit-bot: I haz the power, 2015-05-15 15:37:11]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1126333005/140001

[commit-bot: I haz the power, 2015-05-15 15:41:58]

Committed patchset #8 (id:140001)

[commit-bot: I haz the power, 2015-05-15 15:42:54]

Patchset 8 (id:??) landed as
https://crrev.com/c343193276d07ebb2b184a790e5c0f60d2f98cd3
Cr-Commit-Position: refs/heads/master@{#330099}