Add flag for App Service Intent Handling.

This CL adds a feature flag for using the App Service to provide data
for intent handling.

BUG=853604

Change-Id: I3d67dcb56071bc958e598459fb2c68fdc2d9fd4f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1792034
Commit-Queue: Maggie Cai <[email protected]>
Reviewed-by: Dominick Ng <[email protected]>
Cr-Commit-Position: refs/heads/master@{#694674}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 46451aa..90c42fb 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1826,6 +1826,9 @@
 extern const char kAppServiceAshName[];
 extern const char kAppServiceAshDescription[];
 
+extern const char kAppServiceIntentHandlingName[];
+extern const char kAppServiceIntentHandlingDescription[];
+
 extern const char kAppServiceShelfName[];
 extern const char kAppServiceShelfDescription[];