Adds a new flag for Stylus Rich Gestures.

This flag will be used across both Chrome and Webview and though it lives in native, will be accessed from Java.

Change-Id: If7c7025c90ed61a090e487db3ab1640a40183e43
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4219751
Commit-Queue: Alex Mitra <[email protected]>
Reviewed-by: Robert Flack <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1103212}
diff --git a/chrome/browser/flag_descriptions.cc b/chrome/browser/flag_descriptions.cc
index 235ec334..bfc3c821 100644
--- a/chrome/browser/flag_descriptions.cc
+++ b/chrome/browser/flag_descriptions.cc
@@ -4040,6 +4040,11 @@
     "#site-isolation-trial-opt-out for how to disable site isolation for "
     "testing.";
 
+const char kStylusRichGesturesName[] = "Stylus rich gestures";
+const char kStylusRichGesturesDescription[] =
+    "Enable rich gestures for stylus which can be used to modify text in "
+    "editable web content.";
+
 const char kTabGroupsForTabletsName[] = "Tab groups on tablets";
 const char kTabGroupsForTabletsDescription[] = "Enable tab groups on tablets.";