diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 05d42ada..cd63090 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -1669,7 +1669,7 @@
     final void setFocusedActivityLocked(ActivityRecord r) {
         if (mFocusedActivity != r) {
             mFocusedActivity = r;
-            mWindowManager.setFocusedApp(r, true);
+            mWindowManager.setFocusedApp(r.appToken, true);
         }
     }
 
@@ -2346,7 +2346,8 @@
             // XXX we are not dealing with propagating grantedUriPermissions...
             // those are not yet exposed to user code, so there is no need.
             int res = mMainStack.startActivityLocked(r.app.thread, intent,
-                    r.resolvedType, null, 0, aInfo, resultTo, resultWho,
+                    r.resolvedType, null, 0, aInfo,
+                    resultTo != null ? resultTo.appToken : null, resultWho,
                     requestCode, -1, r.launchedFromUid, false, false, null);
             Binder.restoreCallingIdentity(origId);
 
@@ -2429,10 +2430,10 @@
                 return;
             }
             final long origId = Binder.clearCallingIdentity();
-            mWindowManager.setAppOrientation(r, requestedOrientation);
+            mWindowManager.setAppOrientation(r.appToken, requestedOrientation);
             Configuration config = mWindowManager.updateOrientationFromAppTokens(
                     mConfiguration,
-                    r.mayFreezeScreenLocked(r.app) ? r : null);
+                    r.mayFreezeScreenLocked(r.app) ? r.appToken : null);
             if (config != null) {
                 r.frozenBeforeDestroy = true;
                 if (!updateConfigurationLocked(config, r, false)) {
@@ -2449,7 +2450,7 @@
             if (r == null) {
                 return ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
             }
-            return mWindowManager.getAppOrientation(r);
+            return mWindowManager.getAppOrientation(r.appToken);
         }
     }
 
@@ -2515,7 +2516,7 @@
             for (int i=0; i<activities.size(); i++) {
                 ActivityRecord r = activities.get(i);
                 if (!r.finishing) {
-                    int index = mMainStack.indexOfTokenLocked(r);
+                    int index = mMainStack.indexOfTokenLocked(r.appToken);
                     if (index >= 0) {
                         mMainStack.finishActivityLocked(r, index, Activity.RESULT_CANCELED,
                                 null, "finish-heavy");
@@ -2617,7 +2618,7 @@
             int i;
             for (i=mMainStack.mHistory.size()-1; i>=0; i--) {
                 ActivityRecord r = (ActivityRecord)mMainStack.mHistory.get(i);
-                if (r == token) {
+                if (r.appToken == token) {
                     return true;
                 }
                 if (r.fullscreen && !r.finishing) {
@@ -2705,9 +2706,9 @@
                     r.makeFinishing();
                     mMainStack.mHistory.remove(i);
                     r.takeFromHistory();
-                    mWindowManager.removeAppToken(r);
+                    mWindowManager.removeAppToken(r.appToken);
                     if (VALIDATE_TOKENS) {
-                        mWindowManager.validateAppTokens(mMainStack.mHistory);
+                        mMainStack.validateAppTokensLocked();
                     }
                     r.removeUriPermissionsLocked();
 
@@ -5173,10 +5174,10 @@
         if (topThumbnail != null) {
             if (localLOGV) Slog.v(TAG, "Requesting top thumbnail");
             try {
-                topThumbnail.requestThumbnail(topRecord);
+                topThumbnail.requestThumbnail(topRecord.appToken);
             } catch (Exception e) {
                 Slog.w(TAG, "Exception thrown when requesting thumbnail", e);
-                sendPendingThumbnail(null, topRecord, null, null, true);
+                sendPendingThumbnail(null, topRecord.appToken, null, null, true);
             }
         }
 
@@ -5547,7 +5548,7 @@
         TaskRecord lastTask = null;
         for (int i=0; i<N; i++) {
             ActivityRecord r = (ActivityRecord)mMainStack.mHistory.get(i);
-            if (r == token) {
+            if (r.appToken == token) {
                 if (!onlyRoot || lastTask != r.task) {
                     return r.task.taskId;
                 }
@@ -5568,7 +5569,7 @@
             for (int i=0; i<N; i++) {
                 ActivityRecord r = (ActivityRecord)mMainStack.mHistory.get(i);
                 if (r.realActivity.equals(className)
-                        && r != token && lastTask != r.task) {
+                        && r.appToken != token && lastTask != r.task) {
                     if (r.stack.finishActivityLocked(r, i, Activity.RESULT_CANCELED,
                             null, "others")) {
                         i--;
@@ -7112,7 +7113,7 @@
                 // process, then terminate it to avoid getting in a loop.
                 Slog.w(TAG, "  Force finishing activity "
                         + r.intent.getComponent().flattenToShortString());
-                int index = mMainStack.indexOfTokenLocked(r);
+                int index = mMainStack.indexOfActivityLocked(r);
                 r.stack.finishActivityLocked(r, index,
                         Activity.RESULT_CANCELED, null, "crashed");
                 // Also terminate any activities below it that aren't yet
@@ -8631,8 +8632,8 @@
             try {
                 TransferPipe tp = new TransferPipe();
                 try {
-                    r.app.thread.dumpActivity(tp.getWriteFd().getFileDescriptor(), r,
-                            innerPrefix, args);
+                    r.app.thread.dumpActivity(tp.getWriteFd().getFileDescriptor(),
+                            r.appToken, innerPrefix, args);
                     tp.go(fd);
                 } finally {
                     tp.kill();
@@ -9048,8 +9049,8 @@
                 try {
                     TransferPipe tp = new TransferPipe();
                     try {
-                        r.app.thread.dumpActivity(tp.getWriteFd().getFileDescriptor(), r,
-                                innerPrefix, args);
+                        r.app.thread.dumpActivity(tp.getWriteFd().getFileDescriptor(),
+                                r.appToken, innerPrefix, args);
                         // Short timeout, since blocking here can
                         // deadlock with the application.
                         tp.go(fd, 2000);
diff --git a/services/java/com/android/server/am/ActivityRecord.java b/services/java/com/android/server/am/ActivityRecord.java
index 00e6cb2..951a946 100644
--- a/services/java/com/android/server/am/ActivityRecord.java
+++ b/services/java/com/android/server/am/ActivityRecord.java
@@ -29,6 +29,7 @@
 import android.graphics.Bitmap;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.IBinder;
 import android.os.Message;
 import android.os.Process;
 import android.os.RemoteException;
@@ -48,9 +49,10 @@
 /**
  * An entry in the history stack, representing an activity.
  */
-final class ActivityRecord extends IApplicationToken.Stub {
+final class ActivityRecord {
     final ActivityManagerService service; // owner
     final ActivityStack stack; // owner
+    final IApplicationToken.Stub appToken; // window manager token
     final ActivityInfo info; // all about me
     final int launchedFromUid; // always the uid who started the activity.
     final Intent intent;    // the original intent that generated us
@@ -200,6 +202,70 @@
         }
     }
 
+    static class Token extends IApplicationToken.Stub {
+        final WeakReference<ActivityRecord> weakActivity;
+
+        Token(ActivityRecord activity) {
+            weakActivity = new WeakReference<ActivityRecord>(activity);
+        }
+
+        @Override public void windowsDrawn() throws RemoteException {
+            ActivityRecord activity = weakActivity.get();
+            if (activity != null) {
+                activity.windowsDrawn();
+            }
+        }
+
+        @Override public void windowsVisible() throws RemoteException {
+            ActivityRecord activity = weakActivity.get();
+            if (activity != null) {
+                activity.windowsVisible();
+            }
+        }
+
+        @Override public void windowsGone() throws RemoteException {
+            ActivityRecord activity = weakActivity.get();
+            if (activity != null) {
+                activity.windowsGone();
+            }
+        }
+
+        @Override public boolean keyDispatchingTimedOut() throws RemoteException {
+            ActivityRecord activity = weakActivity.get();
+            if (activity != null) {
+                return activity.keyDispatchingTimedOut();
+            }
+            return false;
+        }
+
+        @Override public long getKeyDispatchingTimeout() throws RemoteException {
+            ActivityRecord activity = weakActivity.get();
+            if (activity != null) {
+                return activity.getKeyDispatchingTimeout();
+            }
+            return 0;
+        }
+
+        public String toString() {
+            StringBuilder sb = new StringBuilder(128);
+            sb.append("Token{");
+            sb.append(Integer.toHexString(System.identityHashCode(this)));
+            sb.append(' ');
+            sb.append(weakActivity.get());
+            sb.append('}');
+            return sb.toString();
+        }
+    }
+
+    static ActivityRecord forToken(IBinder token) {
+        try {
+            return token != null ? ((Token)token).weakActivity.get() : null;
+        } catch (ClassCastException e) {
+            Slog.w(ActivityManagerService.TAG, "Bad activity token: " + token, e);
+            return null;
+        }
+    }
+
     ActivityRecord(ActivityManagerService _service, ActivityStack _stack, ProcessRecord _caller,
             int _launchedFromUid, Intent _intent, String _resolvedType,
             ActivityInfo aInfo, Configuration _configuration,
@@ -207,6 +273,7 @@
             boolean _componentSpecified) {
         service = _service;
         stack = _stack;
+        appToken = new Token(this);
         info = aInfo;
         launchedFromUid = _launchedFromUid;
         intent = _intent;
@@ -445,7 +512,7 @@
                 ar.add(intent);
                 service.grantUriPermissionFromIntentLocked(callingUid, packageName,
                         intent, getUriPermissionsLocked());
-                app.thread.scheduleNewIntent(ar, this);
+                app.thread.scheduleNewIntent(ar, appToken);
                 sent = true;
             } catch (RemoteException e) {
                 Slog.w(ActivityManagerService.TAG,
@@ -470,14 +537,14 @@
     void pauseKeyDispatchingLocked() {
         if (!keysPaused) {
             keysPaused = true;
-            service.mWindowManager.pauseKeyDispatching(this);
+            service.mWindowManager.pauseKeyDispatching(appToken);
         }
     }
 
     void resumeKeyDispatchingLocked() {
         if (keysPaused) {
             keysPaused = false;
-            service.mWindowManager.resumeKeyDispatching(this);
+            service.mWindowManager.resumeKeyDispatching(appToken);
         }
     }
 
@@ -512,14 +579,14 @@
     
     public void startFreezingScreenLocked(ProcessRecord app, int configChanges) {
         if (mayFreezeScreenLocked(app)) {
-            service.mWindowManager.startAppFreezingScreen(this, configChanges);
+            service.mWindowManager.startAppFreezingScreen(appToken, configChanges);
         }
     }
     
     public void stopFreezingScreenLocked(boolean force) {
         if (force || frozenBeforeDestroy) {
             frozenBeforeDestroy = false;
-            service.mWindowManager.stopAppFreezingScreen(this, force);
+            service.mWindowManager.stopAppFreezingScreen(appToken, force);
         }
     }
     
@@ -687,7 +754,7 @@
         }
         if (app != null && app.thread != null) {
             try {
-                app.thread.scheduleSleeping(this, _sleeping);
+                app.thread.scheduleSleeping(appToken, _sleeping);
                 if (sleeping && !stack.mGoingToSleepActivities.contains(this)) {
                     stack.mGoingToSleepActivities.add(this);
                 }
diff --git a/services/java/com/android/server/am/ActivityStack.java b/services/java/com/android/server/am/ActivityStack.java
index 8435eaa..c892cb1 100644
--- a/services/java/com/android/server/am/ActivityStack.java
+++ b/services/java/com/android/server/am/ActivityStack.java
@@ -145,7 +145,12 @@
      * running) activities.  It contains HistoryRecord objects.
      */
     final ArrayList<ActivityRecord> mHistory = new ArrayList<ActivityRecord>();
-    
+
+    /**
+     * Used for validating app tokens with window manager.
+     */
+    final ArrayList<IBinder> mValidateAppTokens = new ArrayList<IBinder>();
+
     /**
      * List of running activities, sorted by recent usage.
      * The first entry in the list is the least recently used.
@@ -294,11 +299,11 @@
                     }
                 } break;
                 case PAUSE_TIMEOUT_MSG: {
-                    IBinder token = (IBinder)msg.obj;
+                    ActivityRecord r = (ActivityRecord)msg.obj;
                     // We don't at this point know if the activity is fullscreen,
                     // so we need to be conservative and assume it isn't.
-                    Slog.w(TAG, "Activity pause timeout for " + token);
-                    activityPaused(token, true);
+                    Slog.w(TAG, "Activity pause timeout for " + r);
+                    activityPaused(r != null ? r.appToken : null, true);
                 } break;
                 case IDLE_TIMEOUT_MSG: {
                     if (mService.mDidDexOpt) {
@@ -310,20 +315,20 @@
                     }
                     // We don't at this point know if the activity is fullscreen,
                     // so we need to be conservative and assume it isn't.
-                    IBinder token = (IBinder)msg.obj;
-                    Slog.w(TAG, "Activity idle timeout for " + token);
-                    activityIdleInternal(token, true, null);
+                    ActivityRecord r = (ActivityRecord)msg.obj;
+                    Slog.w(TAG, "Activity idle timeout for " + r);
+                    activityIdleInternal(r != null ? r.appToken : null, true, null);
                 } break;
                 case DESTROY_TIMEOUT_MSG: {
-                    IBinder token = (IBinder)msg.obj;
+                    ActivityRecord r = (ActivityRecord)msg.obj;
                     // We don't at this point know if the activity is fullscreen,
                     // so we need to be conservative and assume it isn't.
-                    Slog.w(TAG, "Activity destroy timeout for " + token);
-                    activityDestroyed(token);
+                    Slog.w(TAG, "Activity destroy timeout for " + r);
+                    activityDestroyed(r != null ? r.appToken : null);
                 } break;
                 case IDLE_NOW_MSG: {
-                    IBinder token = (IBinder)msg.obj;
-                    activityIdleInternal(token, false, null);
+                    ActivityRecord r = (ActivityRecord)msg.obj;
+                    activityIdleInternal(r != null ? r.appToken : null, false, null);
                 } break;
                 case LAUNCH_TIMEOUT_MSG: {
                     if (mService.mDidDexOpt) {
@@ -397,7 +402,7 @@
         while (i >= 0) {
             ActivityRecord r = mHistory.get(i);
             // Note: the taskId check depends on real taskId fields being non-zero
-            if (!r.finishing && (token != r) && (taskId != r.task.taskId)) {
+            if (!r.finishing && (token != r.appToken) && (taskId != r.task.taskId)) {
                 return r;
             }
             i--;
@@ -406,23 +411,17 @@
     }
 
     final int indexOfTokenLocked(IBinder token) {
-        try {
-            ActivityRecord r = (ActivityRecord)token;
-            return mHistory.indexOf(r);
-        } catch (ClassCastException e) {
-            Slog.w(TAG, "Bad activity token: " + token, e);
-            return -1;
-        }
+        return mHistory.indexOf(ActivityRecord.forToken(token));
+    }
+
+    final int indexOfActivityLocked(ActivityRecord r) {
+        return mHistory.indexOf(r);
     }
 
     final ActivityRecord isInStackLocked(IBinder token) {
-        try {
-            ActivityRecord r = (ActivityRecord)token;
-            if (mHistory.contains(r)) {
-                return r;
-            }
-        } catch (ClassCastException e) {
-            Slog.w(TAG, "Bad activity token: " + token, e);
+        ActivityRecord r = ActivityRecord.forToken(token);
+        if (mHistory.contains(r)) {
+            return r;
         }
         return null;
     }
@@ -517,7 +516,7 @@
             throws RemoteException {
 
         r.startFreezingScreenLocked(app, 0);
-        mService.mWindowManager.setAppVisibility(r, true);
+        mService.mWindowManager.setAppVisibility(r.appToken, true);
 
         // Have the window manager re-evaluate the orientation of
         // the screen based on the new activity order.  Note that
@@ -528,7 +527,7 @@
         if (checkConfig) {
             Configuration config = mService.mWindowManager.updateOrientationFromAppTokens(
                     mService.mConfiguration,
-                    r.mayFreezeScreenLocked(app) ? r : null);
+                    r.mayFreezeScreenLocked(app) ? r.appToken : null);
             mService.updateConfigurationLocked(config, r, false);
         }
 
@@ -590,7 +589,7 @@
                     profileFd = null;
                 }
             }
-            app.thread.scheduleLaunchActivity(new Intent(r.intent), r,
+            app.thread.scheduleLaunchActivity(new Intent(r.intent), r.appToken,
                     System.identityHashCode(r), r.info, mService.mConfiguration,
                     r.compat, r.icicle, results, newIntents, !andResume,
                     mService.isNextTransitionForward(), profileFile, profileFd,
@@ -624,7 +623,7 @@
                       + r.intent.getComponent().flattenToShortString()
                       + ", giving up", e);
                 mService.appDiedLocked(app, app.pid, app.thread);
-                requestFinishActivityLocked(r, Activity.RESULT_CANCELED, null,
+                requestFinishActivityLocked(r.appToken, Activity.RESULT_CANCELED, null,
                         "2nd-crash");
                 return false;
             }
@@ -821,7 +820,7 @@
         }
 
         if (w > 0) {
-            return mService.mWindowManager.screenshotApplications(who, w, h);
+            return mService.mWindowManager.screenshotApplications(who.appToken, w, h);
         }
         return null;
     }
@@ -856,8 +855,8 @@
                 EventLog.writeEvent(EventLogTags.AM_PAUSE_ACTIVITY,
                         System.identityHashCode(prev),
                         prev.shortComponentName);
-                prev.app.thread.schedulePauseActivity(prev, prev.finishing, userLeaving,
-                        prev.configChangeFlags);
+                prev.app.thread.schedulePauseActivity(prev.appToken, prev.finishing,
+                        userLeaving, prev.configChangeFlags);
                 if (mMainStack) {
                     mService.updateUsageStats(prev, false);
                 }
@@ -1129,7 +1128,7 @@
                     if (!r.visible) {
                         if (DEBUG_VISBILITY) Slog.v(
                                 TAG, "Starting and making visible: " + r);
-                        mService.mWindowManager.setAppVisibility(r, true);
+                        mService.mWindowManager.setAppVisibility(r.appToken, true);
                     }
                     if (r != starting) {
                         startSpecificActivityLocked(r, false, false);
@@ -1153,10 +1152,10 @@
                     if (DEBUG_VISBILITY) Slog.v(
                             TAG, "Making visible and scheduling visibility: " + r);
                     try {
-                        mService.mWindowManager.setAppVisibility(r, true);
+                        mService.mWindowManager.setAppVisibility(r.appToken, true);
                         r.sleeping = false;
                         r.app.pendingUiClean = true;
-                        r.app.thread.scheduleWindowVisibility(r, true);
+                        r.app.thread.scheduleWindowVisibility(r.appToken, true);
                         r.stopFreezingScreenLocked(false);
                     } catch (Exception e) {
                         // Just skip on any failure; we'll make it
@@ -1195,13 +1194,13 @@
                                 TAG, "Making invisible: " + r);
                         r.visible = false;
                         try {
-                            mService.mWindowManager.setAppVisibility(r, false);
+                            mService.mWindowManager.setAppVisibility(r.appToken, false);
                             if ((r.state == ActivityState.STOPPING
                                     || r.state == ActivityState.STOPPED)
                                     && r.app != null && r.app.thread != null) {
                                 if (DEBUG_VISBILITY) Slog.v(
                                         TAG, "Scheduling invisibility: " + r);
-                                r.app.thread.scheduleWindowVisibility(r, false);
+                                r.app.thread.scheduleWindowVisibility(r.appToken, false);
                             }
                         } catch (Exception e) {
                             // Just skip on any failure; we'll make it
@@ -1351,7 +1350,7 @@
                 // previous should actually be hidden depending on whether the
                 // new one is found to be full-screen or not.
                 if (prev.finishing) {
-                    mService.mWindowManager.setAppVisibility(prev, false);
+                    mService.mWindowManager.setAppVisibility(prev.appToken, false);
                     if (DEBUG_SWITCH) Slog.v(TAG, "Not waiting for visible to hide: "
                             + prev + ", waitingVisible="
                             + (prev != null ? prev.waitingVisible : null)
@@ -1399,8 +1398,8 @@
                             ? WindowManagerPolicy.TRANSIT_ACTIVITY_CLOSE
                             : WindowManagerPolicy.TRANSIT_TASK_CLOSE, false);
                 }
-                mService.mWindowManager.setAppWillBeHidden(prev);
-                mService.mWindowManager.setAppVisibility(prev, false);
+                mService.mWindowManager.setAppWillBeHidden(prev.appToken);
+                mService.mWindowManager.setAppVisibility(prev.appToken, false);
             } else {
                 if (DEBUG_TRANSITION) Slog.v(TAG,
                         "Prepare open transition: prev=" + prev);
@@ -1414,8 +1413,8 @@
                 }
             }
             if (false) {
-                mService.mWindowManager.setAppWillBeHidden(prev);
-                mService.mWindowManager.setAppVisibility(prev, false);
+                mService.mWindowManager.setAppWillBeHidden(prev.appToken);
+                mService.mWindowManager.setAppVisibility(prev.appToken, false);
             }
         } else if (mHistory.size() > 1) {
             if (DEBUG_TRANSITION) Slog.v(TAG,
@@ -1433,7 +1432,7 @@
             if (DEBUG_SWITCH) Slog.v(TAG, "Resume running: " + next);
 
             // This activity is now becoming visible.
-            mService.mWindowManager.setAppVisibility(next, true);
+            mService.mWindowManager.setAppVisibility(next.appToken, true);
 
             ActivityRecord lastResumedActivity = mResumedActivity;
             ActivityState lastState = next.state;
@@ -1457,7 +1456,7 @@
                 synchronized (mService) {
                     Configuration config = mService.mWindowManager.updateOrientationFromAppTokens(
                             mService.mConfiguration,
-                            next.mayFreezeScreenLocked(next.app) ? next : null);
+                            next.mayFreezeScreenLocked(next.app) ? next.appToken : null);
                     if (config != null) {
                         next.frozenBeforeDestroy = true;
                     }
@@ -1496,12 +1495,12 @@
                         if (DEBUG_RESULTS) Slog.v(
                                 TAG, "Delivering results to " + next
                                 + ": " + a);
-                        next.app.thread.scheduleSendResult(next, a);
+                        next.app.thread.scheduleSendResult(next.appToken, a);
                     }
                 }
 
                 if (next.newIntents != null) {
-                    next.app.thread.scheduleNewIntent(next.newIntents, next);
+                    next.app.thread.scheduleNewIntent(next.newIntents, next.appToken);
                 }
 
                 EventLog.writeEvent(EventLogTags.AM_RESUME_ACTIVITY,
@@ -1511,7 +1510,7 @@
                 next.sleeping = false;
                 showAskCompatModeDialogLocked(next);
                 next.app.pendingUiClean = true;
-                next.app.thread.scheduleResumeActivity(next,
+                next.app.thread.scheduleResumeActivity(next.appToken,
                         mService.isNextTransitionForward());
                 
                 checkReadyForSleepLocked();
@@ -1528,7 +1527,7 @@
                 } else {
                     if (SHOW_APP_STARTING_PREVIEW && mMainStack) {
                         mService.mWindowManager.setAppStartingWindow(
-                                next, next.packageName, next.theme,
+                                next.appToken, next.packageName, next.theme,
                                 mService.compatibilityInfoForPackageLocked(
                                         next.info.applicationInfo),
                                 next.nonLocalizedLabel,
@@ -1549,7 +1548,7 @@
                 // If any exception gets thrown, toss away this
                 // activity and try the next one.
                 Slog.w(TAG, "Exception thrown during resume of " + next, e);
-                requestFinishActivityLocked(next, Activity.RESULT_CANCELED, null,
+                requestFinishActivityLocked(next.appToken, Activity.RESULT_CANCELED, null,
                         "resume-exception");
                 return true;
             }
@@ -1567,7 +1566,7 @@
             } else {
                 if (SHOW_APP_STARTING_PREVIEW) {
                     mService.mWindowManager.setAppStartingWindow(
-                            next, next.packageName, next.theme,
+                            next.appToken, next.packageName, next.theme,
                             mService.compatibilityInfoForPackageLocked(
                                     next.info.applicationInfo),
                             next.nonLocalizedLabel,
@@ -1610,10 +1609,10 @@
                         }
                         mHistory.add(addPos, r);
                         r.putInHistory();
-                        mService.mWindowManager.addAppToken(addPos, r, r.task.taskId,
+                        mService.mWindowManager.addAppToken(addPos, r.appToken, r.task.taskId,
                                 r.info.screenOrientation, r.fullscreen);
                         if (VALIDATE_TOKENS) {
-                            mService.mWindowManager.validateAppTokens(mHistory);
+                            validateAppTokensLocked();
                         }
                         return;
                     }
@@ -1677,7 +1676,7 @@
                 mNoAnimActivities.remove(r);
             }
             mService.mWindowManager.addAppToken(
-                    addPos, r, r.task.taskId, r.info.screenOrientation, r.fullscreen);
+                    addPos, r.appToken, r.task.taskId, r.info.screenOrientation, r.fullscreen);
             boolean doShow = true;
             if (newTask) {
                 // Even though this activity is starting fresh, we still need
@@ -1705,19 +1704,20 @@
                     else if (prev.nowVisible) prev = null;
                 }
                 mService.mWindowManager.setAppStartingWindow(
-                        r, r.packageName, r.theme,
+                        r.appToken, r.packageName, r.theme,
                         mService.compatibilityInfoForPackageLocked(
                                 r.info.applicationInfo), r.nonLocalizedLabel,
-                        r.labelRes, r.icon, r.windowFlags, prev, showStartingIcon);
+                        r.labelRes, r.icon, r.windowFlags,
+                        prev != null ? prev.appToken : null, showStartingIcon);
             }
         } else {
             // If this is the first activity, don't do any fancy animations,
             // because there is nothing for it to animate on top of.
-            mService.mWindowManager.addAppToken(addPos, r, r.task.taskId,
+            mService.mWindowManager.addAppToken(addPos, r.appToken, r.task.taskId,
                     r.info.screenOrientation, r.fullscreen);
         }
         if (VALIDATE_TOKENS) {
-            mService.mWindowManager.validateAppTokens(mHistory);
+            validateAppTokensLocked();
         }
 
         if (doResume) {
@@ -1725,6 +1725,15 @@
         }
     }
 
+    final void validateAppTokensLocked() {
+        mValidateAppTokens.clear();
+        mValidateAppTokens.ensureCapacity(mHistory.size());
+        for (int i=0; i<mHistory.size(); i++) {
+            mValidateAppTokens.add(mHistory.get(i).appToken);
+        }
+        mService.mWindowManager.validateAppTokens(mValidateAppTokens);
+    }
+
     /**
      * Perform a reset of the given task, if needed as part of launching it.
      * Returns the new HistoryRecord at the top of the task.
@@ -1826,7 +1835,7 @@
                             if (DEBUG_TASKS) Slog.v(TAG, "Start pushing activity " + target
                                     + " out to new task " + target.task);
                         }
-                        mService.mWindowManager.setAppGroupId(target, task.taskId);
+                        mService.mWindowManager.setAppGroupId(target.appToken, task.taskId);
                         if (replyChainEnd < 0) {
                             replyChainEnd = targetI;
                         }
@@ -1849,11 +1858,11 @@
                             }
                             mHistory.remove(srcPos);
                             mHistory.add(dstPos, p);
-                            mService.mWindowManager.moveAppToken(dstPos, p);
-                            mService.mWindowManager.setAppGroupId(p, p.task.taskId);
+                            mService.mWindowManager.moveAppToken(dstPos, p.appToken);
+                            mService.mWindowManager.setAppGroupId(p.appToken, p.task.taskId);
                             dstPos++;
                             if (VALIDATE_TOKENS) {
-                                mService.mWindowManager.validateAppTokens(mHistory);
+                                validateAppTokensLocked();
                             }
                             i++;
                         }
@@ -1985,10 +1994,10 @@
                         mHistory.add(lastReparentPos, p);
                         if (DEBUG_TASKS) Slog.v(TAG, "Pulling activity " + p
                                 + " in to resetting task " + task);
-                        mService.mWindowManager.moveAppToken(lastReparentPos, p);
-                        mService.mWindowManager.setAppGroupId(p, p.task.taskId);
+                        mService.mWindowManager.moveAppToken(lastReparentPos, p.appToken);
+                        mService.mWindowManager.setAppGroupId(p.appToken, p.task.taskId);
                         if (VALIDATE_TOKENS) {
-                            mService.mWindowManager.validateAppTokens(mHistory);
+                            validateAppTokensLocked();
                         }
                     }
                     replyChainEnd = -1;
@@ -2081,7 +2090,7 @@
                 if (ret.launchMode == ActivityInfo.LAUNCH_MULTIPLE
                         && (launchFlags&Intent.FLAG_ACTIVITY_SINGLE_TOP) == 0) {
                     if (!ret.finishing) {
-                        int index = indexOfTokenLocked(ret);
+                        int index = indexOfTokenLocked(ret.appToken);
                         if (index >= 0) {
                             finishActivityLocked(ret, index, Activity.RESULT_CANCELED,
                                     null, "clear");
@@ -3007,7 +3016,7 @@
                         return res;
                     }
 
-                    resultTo = outActivity[0];
+                    resultTo = outActivity[0] != null ? outActivity[0].appToken : null;
                 }
             }
         } finally {
@@ -3065,7 +3074,7 @@
                 ArrayList<ResultInfo> list = new ArrayList<ResultInfo>();
                 list.add(new ResultInfo(resultWho, requestCode,
                         resultCode, data));
-                r.app.thread.scheduleSendResult(r, list);
+                r.app.thread.scheduleSendResult(r.appToken, list);
                 return;
             } catch (Exception e) {
                 Slog.w(TAG, "Exception thrown sending result to " + r, e);
@@ -3080,7 +3089,7 @@
         if ((r.intent.getFlags()&Intent.FLAG_ACTIVITY_NO_HISTORY) != 0
                 || (r.info.flags&ActivityInfo.FLAG_NO_HISTORY) != 0) {
             if (!r.finishing) {
-                requestFinishActivityLocked(r, Activity.RESULT_CANCELED, null,
+                requestFinishActivityLocked(r.appToken, Activity.RESULT_CANCELED, null,
                         "no-history");
             }
         } else if (r.app != null && r.app.thread != null) {
@@ -3098,9 +3107,9 @@
                 if (DEBUG_VISBILITY) Slog.v(
                         TAG, "Stopping visible=" + r.visible + " for " + r);
                 if (!r.visible) {
-                    mService.mWindowManager.setAppVisibility(r, false);
+                    mService.mWindowManager.setAppVisibility(r.appToken, false);
                 }
-                r.app.thread.scheduleStopActivity(r, r.visible, r.configChangeFlags);
+                r.app.thread.scheduleStopActivity(r.appToken, r.visible, r.configChangeFlags);
                 if (mService.isSleeping()) {
                     r.setSleeping(true);
                 }
@@ -3145,7 +3154,7 @@
                     // normal flow and hide it once we determine that it is
                     // hidden by the activities in front of it.
                     if (localLOGV) Slog.v(TAG, "Before stopping, can hide: " + s);
-                    mService.mWindowManager.setAppVisibility(s, false);
+                    mService.mWindowManager.setAppVisibility(s.appToken, false);
                 }
             }
             if ((!s.waitingVisible || mService.isSleeping()) && remove) {
@@ -3186,14 +3195,14 @@
         boolean enableScreen = false;
 
         synchronized (mService) {
-            if (token != null) {
-                mHandler.removeMessages(IDLE_TIMEOUT_MSG, token);
+            ActivityRecord r = ActivityRecord.forToken(token);
+            if (r != null) {
+                mHandler.removeMessages(IDLE_TIMEOUT_MSG, r);
             }
 
             // Get the activity record.
-            int index = indexOfTokenLocked(token);
+            int index = indexOfActivityLocked(r);
             if (index >= 0) {
-                ActivityRecord r = mHistory.get(index);
                 res = r;
 
                 if (fromTimeout) {
@@ -3413,7 +3422,7 @@
                     : WindowManagerPolicy.TRANSIT_ACTIVITY_CLOSE, false);
     
             // Tell window manager to prepare for this one to be removed.
-            mService.mWindowManager.setAppVisibility(r, false);
+            mService.mWindowManager.setAppVisibility(r.appToken, false);
                 
             if (mPausingActivity == null) {
                 if (DEBUG_PAUSE) Slog.v(TAG, "Finish needs to pause: " + r);
@@ -3440,7 +3449,7 @@
 
     private final ActivityRecord finishCurrentActivityLocked(ActivityRecord r,
             int mode) {
-        final int index = indexOfTokenLocked(r);
+        final int index = indexOfActivityLocked(r);
         if (index < 0) {
             return null;
         }
@@ -3570,9 +3579,9 @@
             if (DEBUG_STATES) Slog.v(TAG, "Moving to DESTROYED: " + r
                     + " (removed from history)");
             r.state = ActivityState.DESTROYED;
-            mService.mWindowManager.removeAppToken(r);
+            mService.mWindowManager.removeAppToken(r.appToken);
             if (VALIDATE_TOKENS) {
-                mService.mWindowManager.validateAppTokens(mHistory);
+                validateAppTokensLocked();
             }
             cleanUpActivityServicesLocked(r);
             r.removeUriPermissionsLocked();
@@ -3653,7 +3662,7 @@
             
             try {
                 if (DEBUG_SWITCH) Slog.i(TAG, "Destroying: " + r);
-                r.app.thread.scheduleDestroyActivity(r, r.finishing,
+                r.app.thread.scheduleDestroyActivity(r.appToken, r.finishing,
                         r.configChangeFlags);
             } catch (Exception e) {
                 // We can just ignore exceptions here...  if the process
@@ -3712,11 +3721,13 @@
 
     final void activityDestroyed(IBinder token) {
         synchronized (mService) {
-            mHandler.removeMessages(DESTROY_TIMEOUT_MSG, token);
+            ActivityRecord r = ActivityRecord.forToken(token);
+            if (r != null) {
+                mHandler.removeMessages(DESTROY_TIMEOUT_MSG, r);
+            }
             
-            int index = indexOfTokenLocked(token);
+            int index = indexOfActivityLocked(r);
             if (index >= 0) {
-                ActivityRecord r = mHistory.get(index);
                 if (r.state == ActivityState.DESTROYING) {
                     final long origId = Binder.clearCallingIdentity();
                     removeActivityFromHistoryLocked(r);
@@ -3781,7 +3792,7 @@
             return;
         }
 
-        ArrayList moved = new ArrayList();
+        ArrayList<IBinder> moved = new ArrayList<IBinder>();
 
         // Applying the affinities may have removed entries from the history,
         // so get the size again.
@@ -3803,7 +3814,7 @@
                 }
                 mHistory.remove(pos);
                 mHistory.add(top, r);
-                moved.add(0, r);
+                moved.add(0, r.appToken);
                 top--;
             }
             pos--;
@@ -3826,7 +3837,7 @@
         
         mService.mWindowManager.moveAppTokensToTop(moved);
         if (VALIDATE_TOKENS) {
-            mService.mWindowManager.validateAppTokens(mHistory);
+            validateAppTokensLocked();
         }
 
         finishTaskMoveLocked(task);
@@ -3873,7 +3884,7 @@
             }
         }
 
-        ArrayList moved = new ArrayList();
+        ArrayList<IBinder> moved = new ArrayList<IBinder>();
 
         if (DEBUG_TRANSITION) Slog.v(TAG,
                 "Prepare to back transition: task=" + task);
@@ -3898,7 +3909,7 @@
                 }
                 mHistory.remove(pos);
                 mHistory.add(bottom, r);
-                moved.add(r);
+                moved.add(r.appToken);
                 bottom++;
             }
             pos++;
@@ -3918,7 +3929,7 @@
         }
         mService.mWindowManager.moveAppTokensToBottom(moved);
         if (VALIDATE_TOKENS) {
-            mService.mWindowManager.validateAppTokens(mHistory);
+            validateAppTokensLocked();
         }
 
         finishTaskMoveLocked(task);
@@ -4148,7 +4159,7 @@
         if (r.app != null && r.app.thread != null) {
             try {
                 if (DEBUG_CONFIGURATION) Slog.v(TAG, "Sending new config to " + r);
-                r.app.thread.scheduleActivityConfigurationChanged(r);
+                r.app.thread.scheduleActivityConfigurationChanged(r.appToken);
             } catch (RemoteException e) {
                 // If process died, whatever.
             }
@@ -4178,7 +4189,7 @@
         try {
             if (DEBUG_SWITCH) Slog.i(TAG, "Switch is restarting resumed " + r);
             r.forceNewConfig = false;
-            r.app.thread.scheduleRelaunchActivity(r, results, newIntents,
+            r.app.thread.scheduleRelaunchActivity(r.appToken, results, newIntents,
                     changes, !andResume, mService.mConfiguration);
             // Note: don't need to call pauseIfSleepingLocked() here, because
             // the caller will only pass in 'andResume' if this activity is
diff --git a/services/java/com/android/server/wm/WindowManagerService.java b/services/java/com/android/server/wm/WindowManagerService.java
index 4ffc201..50321b3 100644
--- a/services/java/com/android/server/wm/WindowManagerService.java
+++ b/services/java/com/android/server/wm/WindowManagerService.java
@@ -3070,7 +3070,7 @@
     // Application Window Tokens
     // -------------------------------------------------------------
 
-    public void validateAppTokens(List tokens) {
+    public void validateAppTokens(List<IBinder> tokens) {
         int v = tokens.size()-1;
         int m = mAppTokens.size()-1;
         while (v >= 0 && m >= 0) {