diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 750b1eddd2229..dab11088b1308 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -3017,6 +3017,10 @@ public final class ViewRootImpl implements ViewParent,
         if ((relayoutResult & WindowManagerGlobal.RELAYOUT_RES_FIRST_TIME) != 0) {
             reportNextDraw();
         }
+        if ((relayoutResult & WindowManagerGlobal.RELAYOUT_RES_BLAST_SYNC) != 0) {
+            reportNextDraw();
+            setUseBLASTSyncTransaction();
+        }
 
         boolean cancelDraw = mAttachInfo.mTreeObserver.dispatchOnPreDraw() || !isViewVisible;
 
@@ -3725,7 +3729,7 @@ public final class ViewRootImpl implements ViewParent,
             if (needFrameCompleteCallback) {
                 final Handler handler = mAttachInfo.mHandler;
                 mAttachInfo.mThreadedRenderer.setFrameCompleteCallback((long frameNr) -> {
-                        finishBLASTSync();
+                        finishBLASTSync(!reportNextDraw);
                         handler.postAtFrontOfQueue(() -> {
                             if (reportNextDraw) {
                                 // TODO: Use the frame number
@@ -3759,7 +3763,7 @@ public final class ViewRootImpl implements ViewParent,
             if (usingAsyncReport && !canUseAsync) {
                 mAttachInfo.mThreadedRenderer.setFrameCompleteCallback(null);
                 usingAsyncReport = false;
-                finishBLASTSync();
+                finishBLASTSync(true /* apply */);
             }
         } finally {
             mIsDrawing = false;
@@ -9576,10 +9580,15 @@ public final class ViewRootImpl implements ViewParent,
         mNextDrawUseBLASTSyncTransaction = true;
     }
 
-    private void finishBLASTSync() {
+    private void finishBLASTSync(boolean apply) {
         if (mNextReportConsumeBLAST) {
             mNextReportConsumeBLAST = false;
-            mRtBLASTSyncTransaction.apply();
+
+            if (apply) {
+                mRtBLASTSyncTransaction.apply();
+            } else {
+                mSurfaceChangedTransaction.merge(mRtBLASTSyncTransaction);
+            }
         }
     }
 
diff --git a/core/java/android/view/WindowManagerGlobal.java b/core/java/android/view/WindowManagerGlobal.java
index 410d9afe73daa..ab968d798745d 100644
--- a/core/java/android/view/WindowManagerGlobal.java
+++ b/core/java/android/view/WindowManagerGlobal.java
@@ -101,6 +101,14 @@ public final class WindowManagerGlobal {
      */
     public static final int RELAYOUT_RES_CONSUME_ALWAYS_SYSTEM_BARS = 0x40;
 
+    /**
+     * This flag indicates the client should not directly submit it's next frame,
+     * but instead should pass it in the postDrawTransaction of
+     * {@link WindowManagerService#finishDrawing}. This is used by the WM
+     * BLASTSyncEngine to synchronize rendering of multiple windows.
+     */
+    public static final int RELAYOUT_RES_BLAST_SYNC = 0x80;
+
     /**
      * Flag for relayout: the client will be later giving
      * internal insets; as a result, the window will not impact other window
diff --git a/services/core/java/com/android/server/wm/WindowContainer.java b/services/core/java/com/android/server/wm/WindowContainer.java
index f6e952c4cea15..3c0eb88d90fce 100644
--- a/services/core/java/com/android/server/wm/WindowContainer.java
+++ b/services/core/java/com/android/server/wm/WindowContainer.java
@@ -2577,4 +2577,8 @@ class WindowContainer<E extends WindowContainer> extends ConfigurationContainer<
 
         return willSync;
     }
+
+    boolean useBLASTSync() {
+        return mUsingBLASTSyncTransaction;
+    }
 }
diff --git a/services/core/java/com/android/server/wm/WindowManagerService.java b/services/core/java/com/android/server/wm/WindowManagerService.java
index dea2e9644f0a9..c3fb68f9e0c45 100644
--- a/services/core/java/com/android/server/wm/WindowManagerService.java
+++ b/services/core/java/com/android/server/wm/WindowManagerService.java
@@ -73,6 +73,7 @@ import static android.view.WindowManager.LayoutParams.TYPE_WALLPAPER;
 import static android.view.WindowManager.REMOVE_CONTENT_MODE_UNDEFINED;
 import static android.view.WindowManagerGlobal.ADD_OKAY;
 import static android.view.WindowManagerGlobal.RELAYOUT_DEFER_SURFACE_DESTROY;
+import static android.view.WindowManagerGlobal.RELAYOUT_RES_BLAST_SYNC;
 import static android.view.WindowManagerGlobal.RELAYOUT_RES_SURFACE_CHANGED;
 import static android.view.WindowManagerPolicyConstants.NAV_BAR_INVALID;
 
@@ -2110,6 +2111,10 @@ public class WindowManagerService extends IWindowManager.Stub
                 win.finishSeamlessRotation(false /* timeout */);
             }
 
+            if (win.useBLASTSync()) {
+                result |= RELAYOUT_RES_BLAST_SYNC;
+            }
+
             int attrChanges = 0;
             int flagChanges = 0;
             int privateFlagChanges = 0;
diff --git a/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskOrganizerMultiWindowTest.java b/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskOrganizerMultiWindowTest.java
index b40d022f075d9..86c3fa0fe0346 100644
--- a/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskOrganizerMultiWindowTest.java
+++ b/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskOrganizerMultiWindowTest.java
@@ -53,8 +53,9 @@ public class TaskOrganizerMultiWindowTest extends Activity {
                 return true;
             }
 
-            float x = e.getX(0);
+            float x = e.getRawX(0);
             float ratio = (float) x / (float) getWidth() ;
+            ratio = 1-ratio;
 
             LinearLayout.LayoutParams lp1 =
                 new LinearLayout.LayoutParams(0,
@@ -172,10 +173,14 @@ public class TaskOrganizerMultiWindowTest extends Activity {
         setContentView(splitView);
     }
 
+    private void addFlags(Intent intent) {
+        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_NO_ANIMATION);
+    }
+
     Intent makeSettingsIntent() {
         Intent intent = new Intent();
         intent.setAction(android.provider.Settings.ACTION_SETTINGS);
-        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        addFlags(intent);
         return intent;
     }
 
@@ -183,7 +188,7 @@ public class TaskOrganizerMultiWindowTest extends Activity {
         Intent intent = new Intent();
         intent.setAction(Intent.ACTION_MAIN);
         intent.addCategory(Intent.CATEGORY_APP_CONTACTS);
-        intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        addFlags(intent);
         return intent;
     }
 
diff --git a/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskView.java b/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskView.java
index 03615f3327233..aa041f22a46ed 100644
--- a/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskView.java
+++ b/tests/TaskOrganizerTest/src/com/android/test/taskembed/TaskView.java
@@ -80,8 +80,10 @@ class TaskView extends SurfaceView implements SurfaceHolder.Callback {
         } catch (Exception e) {
             // System server died.. oh well
         }
+
         t.reparent(leash, getSurfaceControl())
             .setPosition(leash, 0, 0)
+            .show(leash)
             .apply();
     }
 }