diff --git a/core/java/android/provider/Settings.java b/core/java/android/provider/Settings.java
index 11effd0..a1f9743 100644
--- a/core/java/android/provider/Settings.java
+++ b/core/java/android/provider/Settings.java
@@ -6277,6 +6277,15 @@
         */
        public static final String FORCE_ALLOW_ON_EXTERNAL = "force_allow_on_external";
 
+        /**
+         * Whether any activity can be resized. When this is true, any
+         * activity, regardless of manifest values, can be resized for multi-window.
+         * (0 = false, 1 = true)
+         * @hide
+         */
+        public static final String DEVELOPMENT_FORCE_RESIZABLE_ACTIVITIES
+                = "force_resizable_activities";
+
        /**
         * Whether user has enabled development settings.
         */
diff --git a/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java b/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
index d3559bc..221af15 100644
--- a/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
+++ b/packages/SystemUI/src/com/android/systemui/recents/misc/SystemServicesProxy.java
@@ -266,17 +266,6 @@
         return null;
     }
 
-    /** Allow a task to resize. */
-    public void setTaskResizeable(int taskId) {
-        if (mIam == null) return;
-
-        try {
-            mIam.setTaskResizeable(taskId, true);
-        } catch (RemoteException e) {
-            e.printStackTrace();
-        }
-    }
-
     /**
      * Resizes the given task to the new bounds.
      */
@@ -746,8 +735,6 @@
             ActivityOptions options) {
         if (mIam != null) {
             try {
-                // TODO: Remove when compatibility story is figured out.
-                setTaskResizeable(taskId);
                 mIam.startActivityFromRecents(
                         taskId, INVALID_STACK_ID, options == null ? null : options.toBundle());
                 return true;
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index 9834757..257f034 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -75,6 +75,7 @@
 import android.os.storage.IMountService;
 import android.os.storage.MountServiceInternal;
 import android.os.storage.StorageManager;
+import android.provider.Settings.Global;
 import android.service.voice.IVoiceInteractionSession;
 import android.service.voice.VoiceInteractionSession;
 import android.util.ArrayMap;
@@ -1189,6 +1190,7 @@
     String mOrigDebugApp = null;
     boolean mOrigWaitForDebugger = false;
     boolean mAlwaysFinishActivities = false;
+    boolean mForceResizableActivites;
     IActivityController mController = null;
     String mProfileApp = null;
     ProcessRecord mProfileProc = null;
@@ -11638,14 +11640,17 @@
 
     private void retrieveSettings() {
         final ContentResolver resolver = mContext.getContentResolver();
-        String debugApp = Settings.Global.getString(
-            resolver, Settings.Global.DEBUG_APP);
+        String debugApp = Settings.Global.getString(resolver, Settings.Global.DEBUG_APP);
         boolean waitForDebugger = Settings.Global.getInt(
             resolver, Settings.Global.WAIT_FOR_DEBUGGER, 0) != 0;
         boolean alwaysFinishActivities = Settings.Global.getInt(
             resolver, Settings.Global.ALWAYS_FINISH_ACTIVITIES, 0) != 0;
         boolean forceRtl = Settings.Global.getInt(
                 resolver, Settings.Global.DEVELOPMENT_FORCE_RTL, 0) != 0;
+        int defaultForceResizable = Build.IS_DEBUGGABLE ? 1 : 0;
+        boolean forceResizable = Settings.Global.getInt(
+                resolver, Global.DEVELOPMENT_FORCE_RESIZABLE_ACTIVITIES,
+                defaultForceResizable) != 0;
         // Transfer any global setting for forcing RTL layout, into a System Property
         SystemProperties.set(Settings.Global.DEVELOPMENT_FORCE_RTL, forceRtl ? "1":"0");
 
@@ -11660,6 +11665,7 @@
             mDebugApp = mOrigDebugApp = debugApp;
             mWaitForDebugger = mOrigWaitForDebugger = waitForDebugger;
             mAlwaysFinishActivities = alwaysFinishActivities;
+            mForceResizableActivites = forceResizable;
             // This happens before any activities are started, so we can
             // change mConfiguration in-place.
             updateConfigurationLocked(configuration, null, true);
diff --git a/services/core/java/com/android/server/am/TaskRecord.java b/services/core/java/com/android/server/am/TaskRecord.java
index 090a342..120b40c 100644
--- a/services/core/java/com/android/server/am/TaskRecord.java
+++ b/services/core/java/com/android/server/am/TaskRecord.java
@@ -318,7 +318,7 @@
         mNextAffiliateTaskId = nextTaskId;
         mCallingUid = callingUid;
         mCallingPackage = callingPackage;
-        mResizeable = resizeable;
+        mResizeable = resizeable || mService.mForceResizableActivites;
         mPrivileged = privileged;
         ActivityInfo info = mActivities.get(0).info;
         mMinimalSize = info != null && info.layout != null ? info.layout.minimalSize : -1;
@@ -420,7 +420,7 @@
         } else {
             autoRemoveRecents = false;
         }
-        mResizeable = info.resizeable;
+        mResizeable = info.resizeable || mService.mForceResizableActivites;
         mLockTaskMode = info.lockTaskLaunchMode;
         mPrivileged = (info.applicationInfo.privateFlags & PRIVATE_FLAG_PRIVILEGED) != 0;
         setLockTaskAuth();
@@ -626,6 +626,9 @@
         // Only set this based on the first activity
         if (mActivities.isEmpty()) {
             taskType = r.mActivityType;
+            if (taskType == HOME_ACTIVITY_TYPE && mService.mForceResizableActivites) {
+                mResizeable = r.info.resizeable;
+            }
             isPersistable = r.isPersistable();
             mCallingUid = r.launchedFromUid;
             mCallingPackage = r.launchedFromPackage;