Fix split divider janky

The janky caused by SurfaceFlingerVsyncChoreographer does not work
reliably. Sometimes it didn't update but sometimes update twice per
frame so cause janky.

Fix this by removed using SurfaceFlingerVsyncChoreographer and use
real surface flinger sync signal to update screen.

Bug: 150874701
Test: enter split mode and drag divider to observer janky
Change-Id: I5a8bce36738a97b0ddaf4c4e77949eb5295b4894

1 files changed, 11 insertions, 3 deletions

diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 51304dcfe8cb..9f03652a3f25 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -448,7 +448,7 @@ public final class ViewRootImpl implements ViewParent,
     InputQueue mInputQueue;
     @UnsupportedAppUsage
     FallbackEventHandler mFallbackEventHandler;
-    Choreographer mChoreographer;
+    final Choreographer mChoreographer;
 
     // used in relayout to get SurfaceControl size
     // for BLAST adapter surface setup
@@ -691,11 +691,18 @@ public final class ViewRootImpl implements ViewParent,
     private SurfaceControl.Transaction mRtBLASTSyncTransaction = new SurfaceControl.Transaction();
 
     private String mTag = TAG;
+
     public ViewRootImpl(Context context, Display display) {
-        this(context, display, WindowManagerGlobal.getWindowSession());
+        this(context, display, WindowManagerGlobal.getWindowSession(),
+                false /* useSfChoreographer */);
     }
 
     public ViewRootImpl(Context context, Display display, IWindowSession session) {
+        this(context, display, session, false /* useSfChoreographer */);
+    }
+
+    public ViewRootImpl(Context context, Display display, IWindowSession session,
+            boolean useSfChoreographer) {
         mContext = context;
         mWindowSession = session;
         mDisplay = display;
@@ -731,7 +738,8 @@ public final class ViewRootImpl implements ViewParent,
         mDensity = context.getResources().getDisplayMetrics().densityDpi;
         mNoncompatDensity = context.getResources().getDisplayMetrics().noncompatDensityDpi;
         mFallbackEventHandler = new PhoneFallbackEventHandler(context);
-        mChoreographer = Choreographer.getInstance();
+        mChoreographer = useSfChoreographer
+                ? Choreographer.getSfInstance() : Choreographer.getInstance();
         mDisplayManager = (DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);
         mInsetsController = new InsetsController(this);