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/about_flags.cc b/chrome/browser/about_flags.cc
index cdd5f50d..cce0f06 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -2462,6 +2462,15 @@
      flag_descriptions::kWebUITabStripDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(features::kWebUITabStrip)},
 #endif  // BUILDFLAG(ENABLE_WEBUI_TAB_STRIP)
+#if BUILDFLAG(ENABLE_WEBUI_TAB_STRIP) && defined(OS_CHROMEOS)
+    {
+        "webui-tab-strip-tab-drag-integration",
+        flag_descriptions::kWebUITabStripTabDragIntegrationName,
+        flag_descriptions::kWebUITabStripTabDragIntegrationDescription,
+        kOsCrOS,
+        FEATURE_VALUE_TYPE(ash::features::kWebUITabStripTabDragIntegration),
+    },
+#endif  // BUILDFLAG(ENABLE_WEBUI_TAB_STRIP) && defined(OS_CHROMEOS)
     {"focus-mode", flag_descriptions::kFocusMode,
      flag_descriptions::kFocusModeDescription, kOsDesktop,
      FEATURE_VALUE_TYPE(features::kFocusMode)},