ash: Add metrics for screen lock and shutdown.

ash/shell_delegate.h

Index: ash/shell_delegate.h
diff --git a/ash/shell_delegate.h b/ash/shell_delegate.h
index 8fbfeb32025d000c61cd8d38c7a818af50c0afd1..a5a2744dc77951c1b61f6b7ae4010cba8c34f509 100644
--- a/ash/shell_delegate.h
+++ b/ash/shell_delegate.h
@@ -47,6 +47,9 @@ class UserWallpaperDelegate;
 enum UserMetricsAction {
   UMA_ACCEL_KEYBOARD_BRIGHTNESS_DOWN_F6,
   UMA_ACCEL_KEYBOARD_BRIGHTNESS_UP_F7,
+  UMA_ACCEL_LOCK_SCREEN_L,
+  UMA_ACCEL_LOCK_SCREEN_LOCK_BUTTON,
+  UMA_ACCEL_LOCK_SCREEN_POWER_BUTTON,
   UMA_ACCEL_MAXIMIZE_RESTORE_F4,
   UMA_ACCEL_NEWTAB_T,
   UMA_ACCEL_NEXTWINDOW_F5,
@@ -54,6 +57,7 @@ enum UserMetricsAction {
   UMA_ACCEL_PREVWINDOW_F5,
   UMA_ACCEL_PREVWINDOW_TAB,
   UMA_ACCEL_SEARCH_LWIN,
+  UMA_ACCEL_SHUT_DOWN_POWER_BUTTON,
   UMA_MAXIMIZE_BUTTON_MAXIMIZE,
   UMA_MAXIMIZE_BUTTON_MAXIMIZE_LEFT,
   UMA_MAXIMIZE_BUTTON_MAXIMIZE_RIGHT,
@@ -66,6 +70,9 @@ enum UserMetricsAction {
   UMA_TOGGLE_MAXIMIZE_CAPTION_CLICK,
   UMA_TOGGLE_MAXIMIZE_CAPTION_GESTURE,
   UMA_TOUCHSCREEN_TAP_DOWN,
+  UMA_TRAY_HELP,
+  UMA_TRAY_LOCK_SCREEN,
+  UMA_TRAY_SHUT_DOWN,
 };
 
 enum AccessibilityNotificationVisibility {