Implement system API for monitoring uid importance changes.

Changed the permission for registerUidObserver to be
PACKAGE_USAGE_STATS, which better matches the semantics of this
API and is accessible to system apps.

Test: Added testUidImportanceListener()

Change-Id: Ib47d02bd654fbe399a9c92550c89ecbd38f928dc
diff --git a/api/current.txt b/api/current.txt
index 2e99eaf..22871fa 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -11800,14 +11800,14 @@
     method public deprecated boolean clipRegion(android.graphics.Region);
     method public void concat(android.graphics.Matrix);
     method public void drawARGB(int, int, int, int);
-    method public void drawArc(float, float, float, float, float, float, boolean, android.graphics.Paint);
     method public void drawArc(android.graphics.RectF, float, float, boolean, android.graphics.Paint);
+    method public void drawArc(float, float, float, float, float, float, boolean, android.graphics.Paint);
     method public void drawBitmap(android.graphics.Bitmap, float, float, android.graphics.Paint);
-    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Matrix, android.graphics.Paint);
-    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.Rect, android.graphics.Paint);
     method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.RectF, android.graphics.Paint);
+    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.Rect, android.graphics.Paint);
     method public deprecated void drawBitmap(int[], int, int, float, float, int, int, boolean, android.graphics.Paint);
     method public deprecated void drawBitmap(int[], int, int, int, int, int, int, boolean, android.graphics.Paint);
+    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Matrix, android.graphics.Paint);
     method public void drawBitmapMesh(android.graphics.Bitmap, int, int, float[], int, int[], int, android.graphics.Paint);
     method public void drawCircle(float, float, float, android.graphics.Paint);
     method public void drawColor(int);
@@ -11815,28 +11815,28 @@
     method public void drawLine(float, float, float, float, android.graphics.Paint);
     method public void drawLines(float[], int, int, android.graphics.Paint);
     method public void drawLines(float[], android.graphics.Paint);
-    method public void drawOval(float, float, float, float, android.graphics.Paint);
     method public void drawOval(android.graphics.RectF, android.graphics.Paint);
+    method public void drawOval(float, float, float, float, android.graphics.Paint);
     method public void drawPaint(android.graphics.Paint);
     method public void drawPath(android.graphics.Path, android.graphics.Paint);
     method public void drawPicture(android.graphics.Picture);
-    method public void drawPicture(android.graphics.Picture, android.graphics.Rect);
     method public void drawPicture(android.graphics.Picture, android.graphics.RectF);
+    method public void drawPicture(android.graphics.Picture, android.graphics.Rect);
     method public void drawPoint(float, float, android.graphics.Paint);
     method public void drawPoints(float[], int, int, android.graphics.Paint);
     method public void drawPoints(float[], android.graphics.Paint);
     method public deprecated void drawPosText(char[], int, int, float[], android.graphics.Paint);
     method public deprecated void drawPosText(java.lang.String, float[], android.graphics.Paint);
     method public void drawRGB(int, int, int);
-    method public void drawRect(float, float, float, float, android.graphics.Paint);
-    method public void drawRect(android.graphics.Rect, android.graphics.Paint);
     method public void drawRect(android.graphics.RectF, android.graphics.Paint);
-    method public void drawRoundRect(float, float, float, float, float, float, android.graphics.Paint);
+    method public void drawRect(android.graphics.Rect, android.graphics.Paint);
+    method public void drawRect(float, float, float, float, android.graphics.Paint);
     method public void drawRoundRect(android.graphics.RectF, float, float, android.graphics.Paint);
+    method public void drawRoundRect(float, float, float, float, float, float, android.graphics.Paint);
     method public void drawText(char[], int, int, float, float, android.graphics.Paint);
-    method public void drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint);
     method public void drawText(java.lang.String, float, float, android.graphics.Paint);
     method public void drawText(java.lang.String, int, int, float, float, android.graphics.Paint);
+    method public void drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint);
     method public void drawTextOnPath(char[], int, int, android.graphics.Path, float, float, android.graphics.Paint);
     method public void drawTextOnPath(java.lang.String, android.graphics.Path, float, float, android.graphics.Paint);
     method public void drawTextRun(char[], int, int, int, int, float, float, boolean, android.graphics.Paint);
@@ -32103,6 +32103,15 @@
     field public static final java.lang.String MIME_TYPE_DIR = "vnd.android.document/directory";
   }
 
+  public static final class DocumentsContract.Path implements android.os.Parcelable {
+    ctor public DocumentsContract.Path(java.lang.String, java.util.List<java.lang.String>);
+    method public int describeContents();
+    method public java.util.List<java.lang.String> getPath();
+    method public java.lang.String getRootId();
+    method public void writeToParcel(android.os.Parcel, int);
+    field public static final android.os.Parcelable.Creator<android.provider.DocumentsContract.Path> CREATOR;
+  }
+
   public static final class DocumentsContract.Root {
     field public static final java.lang.String COLUMN_AVAILABLE_BYTES = "available_bytes";
     field public static final java.lang.String COLUMN_CAPACITY_BYTES = "capacity_bytes";
@@ -32120,15 +32129,6 @@
     field public static final int FLAG_SUPPORTS_SEARCH = 8; // 0x8
   }
 
-  public static final class DocumentsContract.Path implements android.os.Parcelable {
-    ctor public DocumentsContract.Path(java.lang.String, java.util.List<java.lang.String>);
-    method public int describeContents();
-    method public java.util.List<java.lang.String> getPath();
-    method public java.lang.String getRootId();
-    method public void writeToParcel(android.os.Parcel, int);
-    field public static final android.os.Parcelable.Creator<android.provider.DocumentsContract.Path> CREATOR;
-  }
-
   public abstract class DocumentsProvider extends android.content.ContentProvider {
     ctor public DocumentsProvider();
     method public java.lang.String copyDocument(java.lang.String, java.lang.String) throws java.io.FileNotFoundException;
diff --git a/api/system-current.txt b/api/system-current.txt
index d077808..a8a725e 100644
--- a/api/system-current.txt
+++ b/api/system-current.txt
@@ -3819,6 +3819,7 @@
 
   public class ActivityManager {
     method public int addAppTask(android.app.Activity, android.content.Intent, android.app.ActivityManager.TaskDescription, android.graphics.Bitmap);
+    method public void addOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener, int);
     method public boolean clearApplicationUserData();
     method public void clearWatchHeapLimit();
     method public void dumpPackageState(java.io.FileDescriptor, java.lang.String);
@@ -3849,6 +3850,7 @@
     method public void killUid(int, java.lang.String);
     method public void moveTaskToFront(int, int);
     method public void moveTaskToFront(int, int, android.os.Bundle);
+    method public void removeOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener);
     method public deprecated void restartPackage(java.lang.String);
     method public static void setVrThread(int);
     method public void setWatchHeapLimit(long);
@@ -3883,6 +3885,10 @@
     field public long totalMem;
   }
 
+  public static abstract interface ActivityManager.OnUidImportanceListener {
+    method public abstract void onUidImportance(int, int);
+  }
+
   public static class ActivityManager.ProcessErrorStateInfo implements android.os.Parcelable {
     ctor public ActivityManager.ProcessErrorStateInfo();
     method public int describeContents();
@@ -12251,14 +12257,14 @@
     method public deprecated boolean clipRegion(android.graphics.Region);
     method public void concat(android.graphics.Matrix);
     method public void drawARGB(int, int, int, int);
-    method public void drawArc(float, float, float, float, float, float, boolean, android.graphics.Paint);
     method public void drawArc(android.graphics.RectF, float, float, boolean, android.graphics.Paint);
+    method public void drawArc(float, float, float, float, float, float, boolean, android.graphics.Paint);
     method public void drawBitmap(android.graphics.Bitmap, float, float, android.graphics.Paint);
-    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Matrix, android.graphics.Paint);
-    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.Rect, android.graphics.Paint);
     method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.RectF, android.graphics.Paint);
+    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.Rect, android.graphics.Paint);
     method public deprecated void drawBitmap(int[], int, int, float, float, int, int, boolean, android.graphics.Paint);
     method public deprecated void drawBitmap(int[], int, int, int, int, int, int, boolean, android.graphics.Paint);
+    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Matrix, android.graphics.Paint);
     method public void drawBitmapMesh(android.graphics.Bitmap, int, int, float[], int, int[], int, android.graphics.Paint);
     method public void drawCircle(float, float, float, android.graphics.Paint);
     method public void drawColor(int);
@@ -12266,28 +12272,28 @@
     method public void drawLine(float, float, float, float, android.graphics.Paint);
     method public void drawLines(float[], int, int, android.graphics.Paint);
     method public void drawLines(float[], android.graphics.Paint);
-    method public void drawOval(float, float, float, float, android.graphics.Paint);
     method public void drawOval(android.graphics.RectF, android.graphics.Paint);
+    method public void drawOval(float, float, float, float, android.graphics.Paint);
     method public void drawPaint(android.graphics.Paint);
     method public void drawPath(android.graphics.Path, android.graphics.Paint);
     method public void drawPicture(android.graphics.Picture);
-    method public void drawPicture(android.graphics.Picture, android.graphics.Rect);
     method public void drawPicture(android.graphics.Picture, android.graphics.RectF);
+    method public void drawPicture(android.graphics.Picture, android.graphics.Rect);
     method public void drawPoint(float, float, android.graphics.Paint);
     method public void drawPoints(float[], int, int, android.graphics.Paint);
     method public void drawPoints(float[], android.graphics.Paint);
     method public deprecated void drawPosText(char[], int, int, float[], android.graphics.Paint);
     method public deprecated void drawPosText(java.lang.String, float[], android.graphics.Paint);
     method public void drawRGB(int, int, int);
-    method public void drawRect(float, float, float, float, android.graphics.Paint);
-    method public void drawRect(android.graphics.Rect, android.graphics.Paint);
     method public void drawRect(android.graphics.RectF, android.graphics.Paint);
-    method public void drawRoundRect(float, float, float, float, float, float, android.graphics.Paint);
+    method public void drawRect(android.graphics.Rect, android.graphics.Paint);
+    method public void drawRect(float, float, float, float, android.graphics.Paint);
     method public void drawRoundRect(android.graphics.RectF, float, float, android.graphics.Paint);
+    method public void drawRoundRect(float, float, float, float, float, float, android.graphics.Paint);
     method public void drawText(char[], int, int, float, float, android.graphics.Paint);
-    method public void drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint);
     method public void drawText(java.lang.String, float, float, android.graphics.Paint);
     method public void drawText(java.lang.String, int, int, float, float, android.graphics.Paint);
+    method public void drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint);
     method public void drawTextOnPath(char[], int, int, android.graphics.Path, float, float, android.graphics.Paint);
     method public void drawTextOnPath(java.lang.String, android.graphics.Path, float, float, android.graphics.Paint);
     method public void drawTextRun(char[], int, int, int, int, float, float, boolean, android.graphics.Paint);
diff --git a/api/test-current.txt b/api/test-current.txt
index fdaf7a3..50dfa2a 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -3699,6 +3699,7 @@
 
   public class ActivityManager {
     method public int addAppTask(android.app.Activity, android.content.Intent, android.app.ActivityManager.TaskDescription, android.graphics.Bitmap);
+    method public void addOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener, int);
     method public boolean clearApplicationUserData();
     method public void clearWatchHeapLimit();
     method public void dumpPackageState(java.io.FileDescriptor, java.lang.String);
@@ -3712,6 +3713,7 @@
     method public int getMemoryClass();
     method public void getMemoryInfo(android.app.ActivityManager.MemoryInfo);
     method public static void getMyMemoryState(android.app.ActivityManager.RunningAppProcessInfo);
+    method public int getPackageImportance(java.lang.String);
     method public android.os.Debug.MemoryInfo[] getProcessMemoryInfo(int[]);
     method public java.util.List<android.app.ActivityManager.ProcessErrorStateInfo> getProcessesInErrorState();
     method public deprecated java.util.List<android.app.ActivityManager.RecentTaskInfo> getRecentTasks(int, int) throws java.lang.SecurityException;
@@ -3726,6 +3728,7 @@
     method public void killBackgroundProcesses(java.lang.String);
     method public void moveTaskToFront(int, int);
     method public void moveTaskToFront(int, int, android.os.Bundle);
+    method public void removeOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener);
     method public deprecated void restartPackage(java.lang.String);
     method public static void setVrThread(int);
     method public void setWatchHeapLimit(long);
@@ -3760,6 +3763,10 @@
     field public long totalMem;
   }
 
+  public static abstract interface ActivityManager.OnUidImportanceListener {
+    method public abstract void onUidImportance(int, int);
+  }
+
   public static class ActivityManager.ProcessErrorStateInfo implements android.os.Parcelable {
     ctor public ActivityManager.ProcessErrorStateInfo();
     method public int describeContents();
@@ -11818,14 +11825,14 @@
     method public deprecated boolean clipRegion(android.graphics.Region);
     method public void concat(android.graphics.Matrix);
     method public void drawARGB(int, int, int, int);
-    method public void drawArc(float, float, float, float, float, float, boolean, android.graphics.Paint);
     method public void drawArc(android.graphics.RectF, float, float, boolean, android.graphics.Paint);
+    method public void drawArc(float, float, float, float, float, float, boolean, android.graphics.Paint);
     method public void drawBitmap(android.graphics.Bitmap, float, float, android.graphics.Paint);
-    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Matrix, android.graphics.Paint);
-    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.Rect, android.graphics.Paint);
     method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.RectF, android.graphics.Paint);
+    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Rect, android.graphics.Rect, android.graphics.Paint);
     method public deprecated void drawBitmap(int[], int, int, float, float, int, int, boolean, android.graphics.Paint);
     method public deprecated void drawBitmap(int[], int, int, int, int, int, int, boolean, android.graphics.Paint);
+    method public void drawBitmap(android.graphics.Bitmap, android.graphics.Matrix, android.graphics.Paint);
     method public void drawBitmapMesh(android.graphics.Bitmap, int, int, float[], int, int[], int, android.graphics.Paint);
     method public void drawCircle(float, float, float, android.graphics.Paint);
     method public void drawColor(int);
@@ -11833,28 +11840,28 @@
     method public void drawLine(float, float, float, float, android.graphics.Paint);
     method public void drawLines(float[], int, int, android.graphics.Paint);
     method public void drawLines(float[], android.graphics.Paint);
-    method public void drawOval(float, float, float, float, android.graphics.Paint);
     method public void drawOval(android.graphics.RectF, android.graphics.Paint);
+    method public void drawOval(float, float, float, float, android.graphics.Paint);
     method public void drawPaint(android.graphics.Paint);
     method public void drawPath(android.graphics.Path, android.graphics.Paint);
     method public void drawPicture(android.graphics.Picture);
-    method public void drawPicture(android.graphics.Picture, android.graphics.Rect);
     method public void drawPicture(android.graphics.Picture, android.graphics.RectF);
+    method public void drawPicture(android.graphics.Picture, android.graphics.Rect);
     method public void drawPoint(float, float, android.graphics.Paint);
     method public void drawPoints(float[], int, int, android.graphics.Paint);
     method public void drawPoints(float[], android.graphics.Paint);
     method public deprecated void drawPosText(char[], int, int, float[], android.graphics.Paint);
     method public deprecated void drawPosText(java.lang.String, float[], android.graphics.Paint);
     method public void drawRGB(int, int, int);
-    method public void drawRect(float, float, float, float, android.graphics.Paint);
-    method public void drawRect(android.graphics.Rect, android.graphics.Paint);
     method public void drawRect(android.graphics.RectF, android.graphics.Paint);
-    method public void drawRoundRect(float, float, float, float, float, float, android.graphics.Paint);
+    method public void drawRect(android.graphics.Rect, android.graphics.Paint);
+    method public void drawRect(float, float, float, float, android.graphics.Paint);
     method public void drawRoundRect(android.graphics.RectF, float, float, android.graphics.Paint);
+    method public void drawRoundRect(float, float, float, float, float, float, android.graphics.Paint);
     method public void drawText(char[], int, int, float, float, android.graphics.Paint);
-    method public void drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint);
     method public void drawText(java.lang.String, float, float, android.graphics.Paint);
     method public void drawText(java.lang.String, int, int, float, float, android.graphics.Paint);
+    method public void drawText(java.lang.CharSequence, int, int, float, float, android.graphics.Paint);
     method public void drawTextOnPath(char[], int, int, android.graphics.Path, float, float, android.graphics.Paint);
     method public void drawTextOnPath(java.lang.String, android.graphics.Path, float, float, android.graphics.Paint);
     method public void drawTextRun(char[], int, int, int, int, float, float, boolean, android.graphics.Paint);
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index bdca086..9af7d8b 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -22,6 +22,7 @@
 import android.annotation.Nullable;
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
+import android.annotation.TestApi;
 import android.content.pm.ActivityInfo;
 import android.content.res.Configuration;
 import android.graphics.Canvas;
@@ -61,6 +62,7 @@
 import android.os.SystemProperties;
 import android.os.UserHandle;
 import android.text.TextUtils;
+import android.util.ArrayMap;
 import android.util.DisplayMetrics;
 import android.util.Singleton;
 import android.util.Size;
@@ -87,6 +89,49 @@
     private final Context mContext;
     private final Handler mHandler;
 
+    static final class UidObserver extends IUidObserver.Stub {
+        final OnUidImportanceListener mListener;
+        final int mImportanceCutpoint;
+        int mLastImportance;
+
+        UidObserver(OnUidImportanceListener listener, int importanceCutpoint) {
+            mListener = listener;
+            mImportanceCutpoint = importanceCutpoint;
+        }
+
+        @Override
+        public void onUidStateChanged(int uid, int procState) {
+            final boolean lastAboveCut = mLastImportance <= mImportanceCutpoint;
+            final int importance = RunningAppProcessInfo.procStateToImportance(procState);
+            final boolean newAboveCut = importance <= mImportanceCutpoint;
+            /*
+            Log.d(TAG, "Uid " + uid + " state change from " + mLastImportance + " to "
+                    + importance + " @ cut " + mImportanceCutpoint
+                    + ": lastAbove=" + lastAboveCut + " newAbove=" + newAboveCut);
+            */
+            mLastImportance = importance;
+            if (lastAboveCut != newAboveCut) {
+                mListener.onUidImportance(uid, importance);
+            }
+        }
+
+        @Override
+        public void onUidGone(int uid) {
+            mLastImportance = RunningAppProcessInfo.IMPORTANCE_GONE;
+            mListener.onUidImportance(uid, RunningAppProcessInfo.IMPORTANCE_GONE);
+        }
+
+        @Override
+        public void onUidActive(int uid) {
+        }
+
+        @Override
+        public void onUidIdle(int uid) {
+        }
+    }
+
+    final ArrayMap<OnUidImportanceListener, UidObserver> mImportanceListeners = new ArrayMap<>();
+
     /**
      * Defines acceptable types of bugreports.
      * @hide
@@ -3045,11 +3090,11 @@
      * running its code, {@link RunningAppProcessInfo#IMPORTANCE_GONE} is returned.
      * @hide
      */
-    @SystemApi
+    @SystemApi @TestApi
     @RequiresPermission(Manifest.permission.PACKAGE_USAGE_STATS)
     public int getPackageImportance(String packageName) {
         try {
-            int procState = ActivityManagerNative.getDefault().getPackageProcessState(packageName,
+            int procState = getService().getPackageProcessState(packageName,
                     mContext.getOpPackageName());
             return RunningAppProcessInfo.procStateToImportance(procState);
         } catch (RemoteException e) {
@@ -3058,6 +3103,83 @@
     }
 
     /**
+     * Callback to get reports about changes to the importance of a uid.  Use with
+     * {@link #addOnUidImportanceListener}.
+     * @hide
+     */
+    @SystemApi @TestApi
+    public interface OnUidImportanceListener {
+        /**
+         * The importance if a given uid has changed.  Will be one of the importance
+         * values in {@link RunningAppProcessInfo};
+         * {@link RunningAppProcessInfo#IMPORTANCE_GONE IMPORTANCE_GONE} will be reported
+         * when the uid is no longer running at all.  This callback will happen on a thread
+         * from a thread pool, not the main UI thread.
+         * @param uid The uid whose importance has changed.
+         * @param importance The new importance value as per {@link RunningAppProcessInfo}.
+         */
+        void onUidImportance(int uid, int importance);
+    }
+
+    /**
+     * Start monitoring changes to the imoportance of uids running in the system.
+     * @param listener The listener callback that will receive change reports.
+     * @param importanceCutpoint The level of importance in which the caller is interested
+     * in differences.  For example, if {@link RunningAppProcessInfo#IMPORTANCE_PERCEPTIBLE}
+     * is used here, you will receive a call each time a uids importance transitions between
+     * being <= {@link RunningAppProcessInfo#IMPORTANCE_PERCEPTIBLE} and
+     * > {@link RunningAppProcessInfo#IMPORTANCE_PERCEPTIBLE}.
+     *
+     * <p>The caller must hold the {@link android.Manifest.permission#PACKAGE_USAGE_STATS}
+     * permission to use this feature.</p>
+     *
+     * @throws IllegalArgumentException If the listener is already registered.
+     * @throws SecurityException If the caller does not hold
+     * {@link android.Manifest.permission#PACKAGE_USAGE_STATS}.
+     * @hide
+     */
+    @SystemApi @TestApi
+    public void addOnUidImportanceListener(OnUidImportanceListener listener,
+            int importanceCutpoint) {
+        synchronized (this) {
+            if (mImportanceListeners.containsKey(listener)) {
+                throw new IllegalArgumentException("Listener already registered: " + listener);
+            }
+            // TODO: implement the cut point in the system process to avoid IPCs.
+            UidObserver observer = new UidObserver(listener, importanceCutpoint);
+            try {
+                getService().registerUidObserver(observer,
+                        UID_OBSERVER_PROCSTATE | UID_OBSERVER_GONE, mContext.getOpPackageName());
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+            mImportanceListeners.put(listener, observer);
+        }
+    }
+
+    /**
+     * Remove an importance listener that was previously registered with
+     * {@link #addOnUidImportanceListener}.
+     *
+     * @throws IllegalArgumentException If the listener is not registered.
+     * @hide
+     */
+    @SystemApi @TestApi
+    public void removeOnUidImportanceListener(OnUidImportanceListener listener) {
+        synchronized (this) {
+            UidObserver observer = mImportanceListeners.remove(listener);
+            if (observer == null) {
+                throw new IllegalArgumentException("Listener not registered: " + listener);
+            }
+            try {
+                getService().unregisterUidObserver(observer);
+            } catch (RemoteException e) {
+                throw e.rethrowFromSystemServer();
+            }
+        }
+    }
+
+    /**
      * Return global memory state information for the calling process.  This
      * does not fill in all fields of the {@link RunningAppProcessInfo}.  The
      * only fields that will be filled in are
diff --git a/core/java/android/app/IActivityManager.aidl b/core/java/android/app/IActivityManager.aidl
index 2498459..92d67b7 100644
--- a/core/java/android/app/IActivityManager.aidl
+++ b/core/java/android/app/IActivityManager.aidl
@@ -431,7 +431,7 @@
      *              etc.
      */
     void keyguardGoingAway(int flags) = 296;
-    void registerUidObserver(in IUidObserver observer, int which) = 297;
+    void registerUidObserver(in IUidObserver observer, int which, String callingPackage) = 297;
     void unregisterUidObserver(in IUidObserver observer) = 298;
     boolean isAssistDataAllowedOnCurrentActivity() = 299;
     boolean showAssistFromActivity(in IBinder token, in Bundle args) = 300;
diff --git a/services/core/java/com/android/server/AlarmManagerService.java b/services/core/java/com/android/server/AlarmManagerService.java
index 20cca16..8e01e9e 100644
--- a/services/core/java/com/android/server/AlarmManagerService.java
+++ b/services/core/java/com/android/server/AlarmManagerService.java
@@ -938,7 +938,7 @@
 
         try {
             ActivityManagerNative.getDefault().registerUidObserver(new UidObserver(),
-                    ActivityManager.UID_OBSERVER_IDLE);
+                    ActivityManager.UID_OBSERVER_IDLE, null);
         } catch (RemoteException e) {
             // ignored; both services live in system_server
         }
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index dd417d9..2d6832d 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -12245,9 +12245,11 @@
     }
 
     @Override
-    public void registerUidObserver(IUidObserver observer, int which) {
-        enforceCallingPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER,
-                "registerUidObserver()");
+    public void registerUidObserver(IUidObserver observer, int which, String callingPackage) {
+        if (!hasUsageStatsPermission(callingPackage)) {
+            enforceCallingPermission(android.Manifest.permission.PACKAGE_USAGE_STATS,
+                    "registerUidObserver");
+        }
         synchronized (this) {
             mUidObservers.register(observer, which);
         }
diff --git a/services/core/java/com/android/server/job/JobSchedulerService.java b/services/core/java/com/android/server/job/JobSchedulerService.java
index 970da99..a37dfed 100644
--- a/services/core/java/com/android/server/job/JobSchedulerService.java
+++ b/services/core/java/com/android/server/job/JobSchedulerService.java
@@ -824,7 +824,7 @@
             try {
                 ActivityManagerNative.getDefault().registerUidObserver(mUidObserver,
                         ActivityManager.UID_OBSERVER_PROCSTATE | ActivityManager.UID_OBSERVER_GONE
-                        | ActivityManager.UID_OBSERVER_IDLE);
+                        | ActivityManager.UID_OBSERVER_IDLE, null);
             } catch (RemoteException e) {
                 // ignored; both services live in system_server
             }
diff --git a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
index 2bccfee..d8103fc 100644
--- a/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
+++ b/services/core/java/com/android/server/net/NetworkPolicyManagerService.java
@@ -611,7 +611,8 @@
 
             try {
                 mActivityManager.registerUidObserver(mUidObserver,
-                        ActivityManager.UID_OBSERVER_PROCSTATE|ActivityManager.UID_OBSERVER_GONE);
+                        ActivityManager.UID_OBSERVER_PROCSTATE|ActivityManager.UID_OBSERVER_GONE,
+                        null);
                 mNetworkManager.registerObserver(mAlertObserver);
             } catch (RemoteException e) {
                 // ignored; both services live in system_server
diff --git a/services/core/java/com/android/server/pm/ShortcutService.java b/services/core/java/com/android/server/pm/ShortcutService.java
index 3b5abe8..37acf5c 100644
--- a/services/core/java/com/android/server/pm/ShortcutService.java
+++ b/services/core/java/com/android/server/pm/ShortcutService.java
@@ -3677,7 +3677,7 @@
     @VisibleForTesting
     void injectRegisterUidObserver(IUidObserver observer, int which) {
         try {
-            ActivityManagerNative.getDefault().registerUidObserver(observer, which);
+            ActivityManagerNative.getDefault().registerUidObserver(observer, which, null);
         } catch (RemoteException shouldntHappen) {
         }
     }
diff --git a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
index 25a421e..42d9412 100644
--- a/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
+++ b/services/tests/servicestests/src/com/android/server/NetworkPolicyManagerServiceTest.java
@@ -246,7 +246,7 @@
                 Log.d(TAG, "set mUidObserver to " + mUidObserver);
                 return null;
             }
-        }).when(mActivityManager).registerUidObserver(any(), anyInt());
+        }).when(mActivityManager).registerUidObserver(any(), anyInt(), null);
 
         mService = new NetworkPolicyManagerService(mServiceContext, mActivityManager, mStatsService,
                 mNetworkManager, mIpm, mTime, mPolicyDir, true);