Update power manager to track uid state like netstats.

To follow the correct semantics for when restricts due to
device idle can be applied, power manager need to know about
uid process states like net policy so that it can allow
wake locks from apps that are in the foreground.

Since this is being added to a second place, I reworked things
so that the activity manager now keeps track of per-uid process
states and allows apps to register to listen to those, rather
than having to track lower-level process states and transform
them into an overall uid state.  Both net policy and power
manager use this new facility.

Change-Id: I77359164c40d0f36fe1ef296dd9f9c3062431148
diff --git a/core/java/android/app/ActivityManagerNative.java b/core/java/android/app/ActivityManagerNative.java
index 1e9bc54..c83a45b 100644
--- a/core/java/android/app/ActivityManagerNative.java
+++ b/core/java/android/app/ActivityManagerNative.java
@@ -1970,6 +1970,22 @@
             return true;
         }
 
+        case REGISTER_UID_OBSERVER_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            IUidObserver observer = IUidObserver.Stub.asInterface(
+                    data.readStrongBinder());
+            registerUidObserver(observer);
+            return true;
+        }
+
+        case UNREGISTER_UID_OBSERVER_TRANSACTION: {
+            data.enforceInterface(IActivityManager.descriptor);
+            IUidObserver observer = IUidObserver.Stub.asInterface(
+                    data.readStrongBinder());
+            unregisterUidObserver(observer);
+            return true;
+        }
+
         case GET_PACKAGE_ASK_SCREEN_COMPAT_TRANSACTION:
         {
             data.enforceInterface(IActivityManager.descriptor);
@@ -5084,6 +5100,28 @@
         reply.recycle();
     }
 
+    public void registerUidObserver(IUidObserver observer) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeStrongBinder(observer != null ? observer.asBinder() : null);
+        mRemote.transact(REGISTER_UID_OBSERVER_TRANSACTION, data, reply, 0);
+        reply.readException();
+        data.recycle();
+        reply.recycle();
+    }
+
+    public void unregisterUidObserver(IUidObserver observer) throws RemoteException {
+        Parcel data = Parcel.obtain();
+        Parcel reply = Parcel.obtain();
+        data.writeInterfaceToken(IActivityManager.descriptor);
+        data.writeStrongBinder(observer != null ? observer.asBinder() : null);
+        mRemote.transact(UNREGISTER_UID_OBSERVER_TRANSACTION, data, reply, 0);
+        reply.readException();
+        data.recycle();
+        reply.recycle();
+    }
+
     public boolean isIntentSenderTargetedToPackage(IIntentSender sender) throws RemoteException {
         Parcel data = Parcel.obtain();
         Parcel reply = Parcel.obtain();