Skip Tab-to-GTS shrinking animation when current TabModel is empty

Bug: 1034843
Change-Id: Ie09c3a057737d412b135f9630cce3a1064aac7c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1973964
Auto-Submit: Yue Zhang <yuezhanggg@chromium.org>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Commit-Queue: Yue Zhang <yuezhanggg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726070}

chrome/android/features/start_surface/internal/java/src/org/chromium/chrome/features/start_surface/StartSurfaceLayout.java

@@ -160,8 +160,10 @@ public class StartSurfaceLayout extends Layout implements StartSurface.OverviewM
     public void show(long time, boolean animate) {
         super.show(time, animate);
 
-        boolean showShrinkingAnimation =
-                animate && TabFeatureUtilities.isTabToGtsAnimationEnabled();
+        // Skip shrinking animation when there is no tab in current tab model.
+        boolean isCurrentTabModelEmpty = mTabModelSelector.getCurrentModel().getCount() == 0;
+        boolean showShrinkingAnimation = animate && TabFeatureUtilities.isTabToGtsAnimationEnabled()
+                && !isCurrentTabModelEmpty;
         boolean quick = mTabListDelegate.prepareOverview();
         Log.d(TAG, "SkipSlowZooming = " + getSkipSlowZooming());
         if (getSkipSlowZooming()) {