Add feature flag for controlling right click remapping

- Add use-search-click-for-right-click flag which when
  enabled makes search+click remap to right click
  instead of the current behavior of Alt+Click.
- Part of plan to transition to this as default behavior

BUG=chromium:248762

Change-Id: I5ca40faf761de320427af4bb2e1913efdd1907af
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1602973
Commit-Queue: Zentaro Kavanagh <[email protected]>
Reviewed-by: Scott Violet <[email protected]>
Reviewed-by: Bailey Berro <[email protected]>
Cr-Commit-Position: refs/heads/master@{#664277}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 54de6a8..6a6efee5 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1113,6 +1113,9 @@
 extern const char kUserActivationV2Name[];
 extern const char kUserActivationV2Description[];
 
+extern const char kUseSearchClickForRightClickName[];
+extern const char kUseSearchClickForRightClickDescription[];
+
 extern const char kV8VmFutureName[];
 extern const char kV8VmFutureDescription[];