Improve init bootcharting.

Most notably, there's no longer any need to guess an end time.

Bug: http://b/23478578
Bug: http://b/33450491
Test: rebooted with bootcharting on/off
Change-Id: Icb7d6859581da5526d77dfc5aa4d57c9bfbfd7e2
diff --git a/rootdir/init.rc b/rootdir/init.rc
index ecc3ccd..9a1fb23 100644
--- a/rootdir/init.rc
+++ b/rootdir/init.rc
@@ -349,7 +349,7 @@
     # Start bootcharting as soon as possible after the data partition is
     # mounted to collect more data.
     mkdir /data/bootchart 0755 shell shell
-    bootchart_init
+    bootchart start
 
     # Avoid predictable entropy pool. Carry over entropy from previous boot.
     copy /data/system/entropy.dat /dev/urandom
@@ -598,6 +598,9 @@
 on property:sys.powerctl=*
     powerctl ${sys.powerctl}
 
+on property:sys.boot_completed=1
+    bootchart stop
+
 # system server cannot write to /proc/sys files,
 # and chown/chmod does not work for /proc/sys/ entries.
 # So proxy writes through init.