Lock free app animations (6/n): Move back-pressure to new animator

SurfaceFlinger was currently only back-pressuring the old
animation system. Move this to the new SurfaceAnimationRunner,
such that every animation frame is presented on screen.

Test: go/wm-smoke
Test: Insert 16ms sleep statement when applying transaction, make
sure animations are still smooth.
Bug:

Change-Id: I510d22c9c4359659e7a061a26b7adad9c265b734

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

@@ -25,6 +25,7 @@ import android.animation.Animator;
 import android.animation.AnimatorListenerAdapter;
 import android.animation.ValueAnimator;
 import android.annotation.Nullable;
+import android.os.SystemClock;
 import android.util.ArrayMap;
 import android.view.Choreographer;
 import android.view.SurfaceControl;
@@ -195,6 +196,7 @@ class SurfaceAnimationRunner {
     }
 
     private void applyTransaction() {
+        mFrameTransaction.setAnimationTransaction();
         mFrameTransaction.apply();
         mApplyScheduled = false;
     }

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

@@ -140,16 +140,6 @@ public class WindowAnimator {
             scheduleAnimation();
         }
 
-        // Simulate back-pressure by opening and closing an empty animation transaction. This makes
-        // sure that an animation frame is at least presented once on the screen. We do this outside
-        // of the regular transaction such that we can avoid holding the window manager lock in case
-        // we receive back-pressure from SurfaceFlinger. Since closing an animation transaction
-        // without the window manager locks leads to ordering issues (as the transaction will be
-        // processed only at the beginning of the next frame which may result in another transaction
-        // that was executed later in WM side gets executed first on SF side), we don't update any
-        // Surface properties here such that reordering doesn't cause issues.
-        mService.executeEmptyAnimationTransaction();
-
         synchronized (mService.mWindowMap) {
             mCurrentTime = frameTimeNs / TimeUtils.NANOS_PER_MS;
             mBulkUpdateParams = SET_ORIENTATION_CHANGE_COMPLETE;

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

@@ -852,35 +852,6 @@ public class WindowManagerService extends IWindowManager.Stub
             Trace.traceEnd(TRACE_TAG_WINDOW_MANAGER);
         }
     }
-
-    /**
-     * Executes an empty animation transaction without holding the WM lock to simulate
-     * back-pressure. See {@link WindowAnimator#animate} why this is needed.
-     */
-    void executeEmptyAnimationTransaction() {
-        try {
-            Trace.traceBegin(TRACE_TAG_WINDOW_MANAGER, "openSurfaceTransaction");
-            synchronized (mWindowMap) {
-                if (mRoot.mSurfaceTraceEnabled) {
-                    mRoot.mRemoteEventTrace.openSurfaceTransaction();
-                }
-                SurfaceControl.openTransaction();
-                SurfaceControl.setAnimationTransaction();
-                if (mRoot.mSurfaceTraceEnabled) {
-                    mRoot.mRemoteEventTrace.closeSurfaceTransaction();
-                }
-            }
-        } finally {
-            Trace.traceEnd(TRACE_TAG_WINDOW_MANAGER);
-        }
-        try {
-            Trace.traceBegin(TRACE_TAG_WINDOW_MANAGER, "closeSurfaceTransaction");
-            SurfaceControl.closeTransaction();
-        } finally {
-            Trace.traceEnd(TRACE_TAG_WINDOW_MANAGER);
-        }
-    }
-
     /** Listener to notify activity manager about app transitions. */
     final WindowManagerInternal.AppTransitionListener mActivityManagerAppTransitionNotifier
             = new WindowManagerInternal.AppTransitionListener() {