Add a feature flag TabToGTSAnimation

This feature controls whether to show the tab-to-GTS transition
animation.

Bug: 964406
Change-Id: Ibcaa215f9c3025f5d0fb69c9c3ad1431ccb4b85c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1622923
Commit-Queue: Wei-Yin Chen (陳威尹) <[email protected]>
Reviewed-by: Yusuf Ozuysal <[email protected]>
Cr-Commit-Position: refs/heads/master@{#662310}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index f23baf4..4a5e7624 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -1751,6 +1751,11 @@
 const char kTabGroupsUiImprovementsAndroidDescription[] =
     "Allows users to access new features in Tab Group UI.";
 
+const char kTabToGTSAnimationAndroidName[] = "Enable Tab-to-GTS Animation";
+const char kTabToGTSAnimationAndroidDescription[] =
+    "Allows users to see an animation when entering or leaving the "
+    "Grid Tab Switcher.";
+
 const char kTabGroupsName[] = "Tab Groups";
 const char kTabGroupsDescription[] =
     "Allows users to organize tabs into visually distinct groups, e.g. to "