Preset remote animation proc for transient launch

So RecentsTransitionHandler#startAnimation ->
setRunningRemoteTransitionDelegate doesn't need to enter wm lock.
That can avoid the latency to notify IRecentsAnimationRunner#
onAnimationStart, e.g. if it is not preset, the set-running-remote
may be blocked by surface placement for several milliseconds.

Reference: I137fcdff3cb5658aad5f7452c33bbc8d70f42398

Bug: 275508603
Test: TransitionTests

Change-Id: Ifa772d7576c42163af2c64a14cee684d117c0b43

services/core/java/com/android/server/wm/ActivityStartController.java

@@ -574,7 +574,9 @@ public class ActivityStartController {
         mService.deferWindowLayout();
         try {
             final TransitionController controller = r.mTransitionController;
-            if (controller.getTransitionPlayer() != null) {
+            final Transition transition = controller.getCollectingTransition();
+            if (transition != null) {
+                transition.setRemoteAnimationApp(r.app.getThread());
                 controller.collect(task);
                 controller.setTransientLaunch(r, TaskDisplayArea.getRootTaskAbove(rootTask));
             }

services/core/java/com/android/server/wm/Transition.java

@@ -66,6 +66,7 @@ import android.annotation.IntDef;
 import android.annotation.NonNull;
 import android.annotation.Nullable;
 import android.app.ActivityManager;
+import android.app.IApplicationThread;
 import android.content.pm.ActivityInfo;
 import android.graphics.Point;
 import android.graphics.Rect;
@@ -83,7 +84,6 @@ import android.util.SparseArray;
 import android.view.Display;
 import android.view.SurfaceControl;
 import android.view.WindowManager;
-import android.window.RemoteTransition;
 import android.window.ScreenCapture;
 import android.window.TransitionInfo;
 
@@ -160,7 +160,7 @@ class Transition implements BLASTSyncEngine.TransactionReadyListener {
     private final TransitionController mController;
     private final BLASTSyncEngine mSyncEngine;
     private final Token mToken;
-    private RemoteTransition mRemoteTransition = null;
+    private IApplicationThread mRemoteAnimApp;
 
     /** Only use for clean-up after binder death! */
     private SurfaceControl.Transaction mStartTransaction = null;
@@ -1075,12 +1075,13 @@ class Transition implements BLASTSyncEngine.TransactionReadyListener {
         return mForcePlaying;
     }
 
-    void setRemoteTransition(RemoteTransition remoteTransition) {
-        mRemoteTransition = remoteTransition;
+    void setRemoteAnimationApp(IApplicationThread app) {
+        mRemoteAnimApp = app;
     }
 
-    RemoteTransition getRemoteTransition() {
-        return mRemoteTransition;
+    /** Returns the app which will run the transition animation. */
+    IApplicationThread getRemoteAnimationApp() {
+        return mRemoteAnimApp;
     }
 
     void setNoAnimation(WindowContainer wc) {

services/core/java/com/android/server/wm/TransitionController.java

@@ -549,7 +549,9 @@ class TransitionController {
             transition.mLogger.mRequestTimeNs = SystemClock.elapsedRealtimeNanos();
             transition.mLogger.mRequest = request;
             mTransitionPlayer.requestStartTransition(transition.getToken(), request);
-            transition.setRemoteTransition(remoteTransition);
+            if (remoteTransition != null) {
+                transition.setRemoteAnimationApp(remoteTransition.getAppThread());
+            }
         } catch (RemoteException e) {
             Slog.e(TAG, "Error requesting transition", e);
             transition.start();
@@ -761,9 +763,8 @@ class TransitionController {
             mRemotePlayer.clear();
             return;
         }
-        final RemoteTransition remote = transition.getRemoteTransition();
-        if (remote == null) return;
-        final IApplicationThread appThread = remote.getAppThread();
+        final IApplicationThread appThread = transition.getRemoteAnimationApp();
+        if (appThread == null || appThread == mTransitionPlayerProc.getThread()) return;
         final WindowProcessController delegate = mAtm.getProcessController(appThread);
         if (delegate == null) return;
         mRemotePlayer.update(delegate, isPlaying, true /* predict */);