CrOS Labs: Overview Desk Navigation

Stay in overview when navigating between desks.

This CL will also makes several other improvements, most notably:
- Prevent users from exiting/entering overview during a desk switch
  animation.
- Short desk switch swipes will now stay in overview.
- Do not animate `save_desk_button_container_widget_` during desk
  animations.

Bug: b/247952417
Test: manual, added OverviewDeskNavigationTest.SwitchDesksWithoutExitingOverview
Change-Id: I0ee3d81709c99403b340e48ac6d47f6a0a0f491f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3709995
Reviewed-by: Ahmed Fakhry <[email protected]>
Commit-Queue: Richard Chui <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1081357}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 9e5c079..a836853ed 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -2232,6 +2232,12 @@
 const char kOverviewButtonDescription[] =
     "If enabled, always show the overview button at the status area.";
 
+const char kOverviewDeskNavigationName[] =
+    "CrOS Labs: Overview Desk Navigation";
+const char kOverviewDeskNavigationDescription[] =
+    "Stay in overview when navigating between desks using a swipe gesture or "
+    "keyboard shortcut.";
+
 const char kPageContentAnnotationsName[] = "Page content annotations";
 const char kPageContentAnnotationsDescription[] =
     "Enables page content to be annotated on-device.";