Add auto-sync decoupling to chrome://flags

This CL makes it easier to test the auto-sync decoupling feature by
adding a corresponding switch to chrome://flags.

Bug: 1105795
Change-Id: I46f4e85aaace65e526fd2b8168b7bb62dc958495
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2438370
Commit-Queue: Victor Vianna <[email protected]>
Reviewed-by: Marc Treib <[email protected]>
Cr-Commit-Position: refs/heads/master@{#811988}
diff --git a/chrome/browser/flag_descriptions.h b/chrome/browser/flag_descriptions.h
index 4a40f5fb..70785ff 100644
--- a/chrome/browser/flag_descriptions.h
+++ b/chrome/browser/flag_descriptions.h
@@ -1567,6 +1567,9 @@
 extern const char kCpuAffinityRestrictToLittleCoresName[];
 extern const char kCpuAffinityRestrictToLittleCoresDescription[];
 
+extern const char kDecoupleSyncFromAndroidAutoSyncName[];
+extern const char kDecoupleSyncFromAndroidAutoSyncDescription[];
+
 extern const char kDirectActionsName[];
 extern const char kDirectActionsDescription[];