Fix scrubbing in timeline with too many windows.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=152003529

library/ui/src/main/java/com/google/android/exoplayer2/ui/PlaybackControlView.java

@@ -817,7 +817,7 @@ public class PlaybackControlView extends FrameLayout {
     public void onScrubStop(TimeBar timeBar, long position, boolean canceled) {
     public void onScrubStop(TimeBar timeBar, long position, boolean canceled) {
       scrubbing = false;
       scrubbing = false;
       if (!canceled && player != null) {
       if (!canceled && player != null) {
-        if (showMultiWindowTimeBar) {
+        if (multiWindowTimeBar) {
           Timeline timeline = player.getCurrentTimeline();
           Timeline timeline = player.getCurrentTimeline();
           int windowCount = timeline.getWindowCount();
           int windowCount = timeline.getWindowCount();
           long remainingMs = position;
           long remainingMs = position;