Added UMA statistics for changing the active window via click or touch events.

ash/metrics/user_metrics_recorder.cc

Index: ash/metrics/user_metrics_recorder.cc
diff --git a/ash/metrics/user_metrics_recorder.cc b/ash/metrics/user_metrics_recorder.cc
index cfc4d8ee16d4a79a28fe463ce86ff38e8f60b497..e3e7ce1658273ce161804a908bd7006885f439bc 100644
--- a/ash/metrics/user_metrics_recorder.cc
+++ b/ash/metrics/user_metrics_recorder.cc
@@ -294,6 +294,11 @@ void UserMetricsRecorder::RecordUserMetricsAction(UserMetricsAction action) {
       base::RecordAction(
           base::UserMetricsAction("Panel_Minimize_Caption_Gesture"));
       break;
+    case ash::UMA_SCREEN_EVENT_SWITCH_TASK:
+      base::RecordAction(base::UserMetricsAction("ScreenEvent_SwitchTask"));

[tdanderson, 2015/05/26 21:13:52]

don't forget to update actions.xml

[bruthig, 2015/06/03 21:59:31]

Done.

+      task_switch_metrics_recorder_.OnTaskSwitch(
+          TaskSwitchMetricsRecorder::kScreen);
+      break;
     case ash::UMA_SHELF_ALIGNMENT_SET_BOTTOM:
       base::RecordAction(
           base::UserMetricsAction("Shelf_AlignmentSetBottom"));