Record WM_BOOT_ANIMATION_DONE in WindowManagerService

to track user-perceived boot performance. Even though we already
have BOOT_PROGRESS_ENABLE_SCREEN, that one is recorded before
WindowManagerService asks bootanim to exit. Since it takes a few
seconds for bootanim to exit (depending on desc.txt in the boot
animation zip file), WM_BOOT_ANIMATION_DONE would represent
user-perceived boot time better.

Bug: 21637637
Change-Id: I9d81dbf3fdb5dcd780e3fc3ca01c8ada4d6f16ef
diff --git a/services/core/java/com/android/server/EventLogTags.logtags b/services/core/java/com/android/server/EventLogTags.logtags
index 49d4c22..15ee123 100644
--- a/services/core/java/com/android/server/EventLogTags.logtags
+++ b/services/core/java/com/android/server/EventLogTags.logtags
@@ -163,6 +163,8 @@
 31005 wm_home_stack_moved (ToTop|1)
 # Stack removed.
 31006 wm_stack_removed (StackId|1|5)
+# bootanim finished:
+31007 wm_boot_animation_done (time|2|3)
 
 
 # ---------------------------