diff --git a/core/java/android/app/ActivityThread.java b/core/java/android/app/ActivityThread.java
index 2a8d64b..26a1c3a 100644
--- a/core/java/android/app/ActivityThread.java
+++ b/core/java/android/app/ActivityThread.java
@@ -46,7 +46,6 @@
 import android.hardware.display.DisplayManagerGlobal;
 import android.net.ConnectivityManager;
 import android.net.IConnectivityManager;
-import android.net.LinkProperties;
 import android.net.Network;
 import android.net.Proxy;
 import android.net.ProxyInfo;
@@ -87,8 +86,6 @@
 import android.util.SuperNotCalledException;
 import android.view.Display;
 import android.view.HardwareRenderer;
-import android.view.IWindowManager;
-import android.view.IWindowSessionCallback;
 import android.view.View;
 import android.view.ViewDebug;
 import android.view.ViewManager;
@@ -165,8 +162,8 @@
     private static final long MIN_TIME_BETWEEN_GCS = 5*1000;
     private static final Pattern PATTERN_SEMICOLON = Pattern.compile(";");
     private static final int SQLITE_MEM_RELEASED_EVENT_LOG_TAG = 75003;
-    private static final int LOG_ON_PAUSE_CALLED = 30021;
-    private static final int LOG_ON_RESUME_CALLED = 30022;
+    private static final int LOG_AM_ON_PAUSE_CALLED = 30021;
+    private static final int LOG_AM_ON_RESUME_CALLED = 30022;
 
     private ContextImpl mSystemContext;
 
@@ -2993,7 +2990,7 @@
                 }
                 r.activity.performResume();
 
-                EventLog.writeEvent(LOG_ON_RESUME_CALLED,
+                EventLog.writeEvent(LOG_AM_ON_RESUME_CALLED,
                         UserHandle.myUserId(), r.activity.getComponentName().getClassName());
 
                 r.paused = false;
@@ -3263,7 +3260,7 @@
             // Now we are idle.
             r.activity.mCalled = false;
             mInstrumentation.callActivityOnPause(r.activity);
-            EventLog.writeEvent(LOG_ON_PAUSE_CALLED, UserHandle.myUserId(),
+            EventLog.writeEvent(LOG_AM_ON_PAUSE_CALLED, UserHandle.myUserId(),
                     r.activity.getComponentName().getClassName());
             if (!r.activity.mCalled) {
                 throw new SuperNotCalledException(
@@ -3660,7 +3657,7 @@
                 try {
                     r.activity.mCalled = false;
                     mInstrumentation.callActivityOnPause(r.activity);
-                    EventLog.writeEvent(LOG_ON_PAUSE_CALLED, UserHandle.myUserId(),
+                    EventLog.writeEvent(LOG_AM_ON_PAUSE_CALLED, UserHandle.myUserId(),
                             r.activity.getComponentName().getClassName());
                     if (!r.activity.mCalled) {
                         throw new SuperNotCalledException(
diff --git a/services/core/java/com/android/server/wm/AppWindowToken.java b/services/core/java/com/android/server/wm/AppWindowToken.java
index 8519f3d..3b27cd2 100644
--- a/services/core/java/com/android/server/wm/AppWindowToken.java
+++ b/services/core/java/com/android/server/wm/AppWindowToken.java
@@ -252,6 +252,20 @@
         return false;
     }
 
+    void removeAppFromTaskLocked() {
+        mIsExiting = false;
+        removeAllWindows();
+
+        final Task task = service.mTaskIdToTask.get(groupId);
+        if (task != null) {
+            if (!task.removeAppToken(this)) {
+                Slog.e(WindowManagerService.TAG, "removeAppFromTaskLocked: token=" + this
+                        + " not found.");
+            }
+            task.mStack.mExitingAppTokens.remove(this);
+        }
+    }
+
     @Override
     void removeAllWindows() {
         for (int winNdx = allAppWindows.size() - 1; winNdx >= 0;
@@ -266,8 +280,10 @@
                 Slog.w(WindowManagerService.TAG, "removeAllWindows: removing win=" + win);
             }
 
-            win.mService.removeWindowLocked(win.mSession, win);
+            service.removeWindowLocked(win.mSession, win);
         }
+        allAppWindows.clear();
+        windows.clear();
     }
 
     @Override
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 45d09211..e3b53b0 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -329,15 +329,9 @@
                     for (int tokenNdx = tokens.size() - 1; tokenNdx >= 0; --tokenNdx) {
                         AppWindowToken wtoken = tokens.get(tokenNdx);
                         if (wtoken.mIsExiting) {
-                            stack.mExitingAppTokens.remove(wtoken);
-                            wtoken.mIsExiting = false;
-                            mService.removeAppFromTaskLocked(wtoken);
+                            wtoken.removeAppFromTaskLocked();
                         }
                     }
-                    if (task.mDeferRemoval) {
-                        task.mDeferRemoval = false;
-                        mService.removeTaskLocked(task);
-                    }
                 }
             }
         }
diff --git a/services/core/java/com/android/server/wm/Task.java b/services/core/java/com/android/server/wm/Task.java
index b49b87c..80d727d 100644
--- a/services/core/java/com/android/server/wm/Task.java
+++ b/services/core/java/com/android/server/wm/Task.java
@@ -17,9 +17,11 @@
 package com.android.server.wm;
 
 import static com.android.server.wm.WindowManagerService.TAG;
+import static com.android.server.wm.WindowManagerService.DEBUG_STACK;
 
 import android.util.EventLog;
 import android.util.Slog;
+import com.android.server.EventLogTags;
 
 class Task {
     TaskStack mStack;
@@ -27,12 +29,14 @@
     final int taskId;
     final int mUserId;
     boolean mDeferRemoval = false;
+    final WindowManagerService mService;
 
-    Task(AppWindowToken wtoken, TaskStack stack, int userId) {
+    Task(AppWindowToken wtoken, TaskStack stack, int userId, WindowManagerService service) {
         taskId = wtoken.groupId;
         mAppTokens.add(wtoken);
         mStack = stack;
         mUserId = userId;
+        mService = service;
     }
 
     DisplayContent getDisplayContent() {
@@ -51,11 +55,27 @@
         mDeferRemoval = false;
     }
 
+    void removeLocked() {
+        if (!mAppTokens.isEmpty() && mStack.isAnimating()) {
+            if (DEBUG_STACK) Slog.i(TAG, "removeTask: deferring removing taskId=" + taskId);
+            mDeferRemoval = true;
+            return;
+        }
+        if (DEBUG_STACK) Slog.i(TAG, "removeTask: removing taskId=" + taskId);
+        EventLog.writeEvent(EventLogTags.WM_TASK_REMOVED, taskId, "removeTask");
+        mDeferRemoval = false;
+        mStack.removeTask(this);
+        mService.mTaskIdToTask.delete(taskId);
+    }
+
     boolean removeAppToken(AppWindowToken wtoken) {
         boolean removed = mAppTokens.remove(wtoken);
         if (mAppTokens.size() == 0) {
             EventLog.writeEvent(com.android.server.EventLogTags.WM_TASK_REMOVED, taskId,
                     "removeAppToken: last token");
+            if (mDeferRemoval) {
+                removeLocked();
+            }
         }
         return removed;
     }
diff --git a/services/core/java/com/android/server/wm/TaskStack.java b/services/core/java/com/android/server/wm/TaskStack.java
index 802cf4b..d6741b3 100644
--- a/services/core/java/com/android/server/wm/TaskStack.java
+++ b/services/core/java/com/android/server/wm/TaskStack.java
@@ -224,6 +224,14 @@
             }
             mDisplayContent.layoutNeeded = true;
         }
+        final int taskId = task.taskId;
+        for (int appNdx = mExitingAppTokens.size() - 1; appNdx >= 0; --appNdx) {
+            final AppWindowToken wtoken = mExitingAppTokens.get(appNdx);
+            if (wtoken.groupId == taskId) {
+                wtoken.mIsExiting = false;
+                mExitingAppTokens.remove(appNdx);
+            }
+        }
     }
 
     void attachDisplayContent(DisplayContent displayContent) {
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index 36ef88e..2c05e93 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -3620,7 +3620,7 @@
             throw new IllegalArgumentException("addAppToken: invalid stackId=" + stackId);
         }
         EventLog.writeEvent(EventLogTags.WM_TASK_CREATED, taskId, stackId);
-        Task task = new Task(atoken, stack, userId);
+        Task task = new Task(atoken, stack, userId, this);
         mTaskIdToTask.put(taskId, task);
         stack.addTask(task, !atoken.mLaunchTaskBehind /* toTop */);
         return task;
@@ -4778,17 +4778,6 @@
         }
     }
 
-    void removeAppFromTaskLocked(AppWindowToken wtoken) {
-        wtoken.removeAllWindows();
-
-        final Task task = mTaskIdToTask.get(wtoken.groupId);
-        if (task != null) {
-            if (!task.removeAppToken(wtoken)) {
-                Slog.e(TAG, "removeAppFromTaskLocked: token=" + wtoken + " not found.");
-            }
-        }
-    }
-
     @Override
     public void removeAppToken(IBinder token) {
         if (!checkCallingPermission(android.Manifest.permission.MANAGE_APP_TOKENS,
@@ -4836,7 +4825,7 @@
                     // soon as their animations are complete
                     wtoken.mAppAnimator.clearAnimation();
                     wtoken.mAppAnimator.animating = false;
-                    removeAppFromTaskLocked(wtoken);
+                    wtoken.removeAppFromTaskLocked();
                 }
 
                 wtoken.removed = true;
@@ -5112,30 +5101,6 @@
         mStackIdToStack.remove(stackId);
     }
 
-    void removeTaskLocked(Task task) {
-        final int taskId = task.taskId;
-        final TaskStack stack = task.mStack;
-        if (!task.mAppTokens.isEmpty() && stack.isAnimating()) {
-            if (DEBUG_STACK) Slog.i(TAG, "removeTask: deferring removing taskId=" + taskId);
-            task.mDeferRemoval = true;
-            return;
-        }
-        if (DEBUG_STACK) Slog.i(TAG, "removeTask: removing taskId=" + taskId);
-        EventLog.writeEvent(EventLogTags.WM_TASK_REMOVED, taskId, "removeTask");
-        task.mDeferRemoval = false;
-        stack.removeTask(task);
-        mTaskIdToTask.delete(task.taskId);
-
-        final ArrayList<AppWindowToken> exitingApps = stack.mExitingAppTokens;
-        for (int appNdx = exitingApps.size() - 1; appNdx >= 0; --appNdx) {
-            final AppWindowToken wtoken = exitingApps.get(appNdx);
-            if (wtoken.groupId == taskId) {
-                wtoken.mIsExiting = false;
-                exitingApps.remove(appNdx);
-            }
-        }
-    }
-
     public void removeTask(int taskId) {
         synchronized (mWindowMap) {
             Task task = mTaskIdToTask.get(taskId);
@@ -5143,7 +5108,7 @@
                 if (DEBUG_STACK) Slog.i(TAG, "removeTask: could not find taskId=" + taskId);
                 return;
             }
-            removeTaskLocked(task);
+            task.removeLocked();
         }
     }
 
@@ -9979,12 +9944,7 @@
                     token.mAppAnimator.animating = false;
                     if (DEBUG_ADD_REMOVE || DEBUG_TOKEN_MOVEMENT) Slog.v(TAG,
                             "performLayout: App token exiting now removed" + token);
-                    removeAppFromTaskLocked(token);
-                    exitingAppTokens.remove(i);
-                    final Task task = mTaskIdToTask.get(token.groupId);
-                    if (task != null && task.mDeferRemoval && task.mAppTokens.isEmpty()) {
-                        removeTaskLocked(task);
-                    }
+                    token.removeAppFromTaskLocked();
                 }
             }
         }
diff --git a/services/core/java/com/android/server/wm/WindowToken.java b/services/core/java/com/android/server/wm/WindowToken.java
index 1a672e68..bbeee8c 100644
--- a/services/core/java/com/android/server/wm/WindowToken.java
+++ b/services/core/java/com/android/server/wm/WindowToken.java
@@ -85,6 +85,7 @@
                     "removeAllWindows: removing win=" + win);
             win.mService.removeWindowLocked(win.mSession, win);
         }
+        windows.clear();
     }
 
     void dump(PrintWriter pw, String prefix) {