Expose WebUITabStripTabDragIntegration flag in chrome://flags

This also updates the expiration of WebUITabStrip which I forgot to extend.

Bug: None
Change-Id: Icba7fc5ce10bb967fe4145662ce6cbe08c96454a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2341823
Commit-Queue: Collin Baker <[email protected]>
Commit-Queue: Xiaoqian Dai <[email protected]>
Reviewed-by: Xiaoqian Dai <[email protected]>
Auto-Submit: Collin Baker <[email protected]>
Cr-Commit-Position: refs/heads/master@{#796026}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 683ad33..0875044 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -2623,6 +2623,11 @@
 extern const char kWebUITabStripDescription[];
 #endif  // BUILDFLAG(ENABLE_WEBUI_TAB_STRIP)
 
+#if BUILDFLAG(ENABLE_WEBUI_TAB_STRIP) && defined(OS_CHROMEOS)
+extern const char kWebUITabStripTabDragIntegrationName[];
+extern const char kWebUITabStripTabDragIntegrationDescription[];
+#endif  // BUILDFLAG(ENABLE_WEBUI_TAB_STRIP) && defined(OS_CHROMEOS)
+
 #if defined(TOOLKIT_VIEWS) || defined(OS_ANDROID)
 
 extern const char kAutofillCreditCardUploadName[];