Added an about-flags entry for enabling the translate message UI.

Bug: 1292788
Change-Id: Id114b6d68a142c2404ad96dc59960daddd180347
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3544307
Reviewed-by: Trevor Perrier <[email protected]>
Commit-Queue: Scott Little <[email protected]>
Cr-Commit-Position: refs/heads/main@{#984472}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index eff0091..ce2ca65b 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -3580,6 +3580,11 @@
     "Enables touch dragging and a context menu to start simultaneously, with"
     "the assumption that the menu is non-modal.";
 
+const char kTranslateMessageUIName[] = "Translate Message UI";
+const char kTranslateMessageUIDescription[] =
+    "Controls whether the Translate Message UI will be shown instead of the "
+    "Translate InfoBar.";
+
 const char kUpdateMenuBadgeName[] = "Force show update menu badge";
 const char kUpdateMenuBadgeDescription[] =
     "When enabled, a badge will be shown on the app menu button if the update "