Remove memory monitoring from the system watchdog

This was originally written as an in-case-we-need-it facility, but was
never actually used in production.  It also soaked up a surprising amount
of cpu on occasion, as well as doing sketchy things like demoting the
system_server's primary looper thread to the background cgroup at times.

Change-Id: I9a81a8d1e9caea9e0a1277d97785fe96add438d7
diff --git a/services/java/com/android/server/am/ProcessRecord.java b/services/java/com/android/server/am/ProcessRecord.java
index 18fd9d6..18b1acb 100644
--- a/services/java/com/android/server/am/ProcessRecord.java
+++ b/services/java/com/android/server/am/ProcessRecord.java
@@ -39,7 +39,7 @@
  * Full information about a particular process that
  * is currently running.
  */
-class ProcessRecord implements Watchdog.PssRequestor {
+class ProcessRecord {
     final BatteryStatsImpl.Uid.Proc batteryStats; // where to collect runtime statistics
     final ApplicationInfo info; // all about the first app in the process
     final String processName;   // name of the process
@@ -264,16 +264,6 @@
         }
     }
     
-    public void requestPss() {
-        IApplicationThread localThread = thread;
-        if (localThread != null) {
-            try {
-                localThread.requestPss();
-            } catch (RemoteException e) {
-            }
-        }
-    }
-    
     public String toShortString() {
         if (shortStringName != null) {
             return shortStringName;