Change behaivor to decide whether a search engine should be shown in the default list

components/sync/protocol/search_engine_specifics.proto

Index: components/sync/protocol/search_engine_specifics.proto
diff --git a/components/sync/protocol/search_engine_specifics.proto b/components/sync/protocol/search_engine_specifics.proto
index e9f3cd9322795374a6a11e6b4d1e8cda94c47145..e58a04fbfc292f3772954faf793c41b6a1757929 100644
--- a/components/sync/protocol/search_engine_specifics.proto
+++ b/components/sync/protocol/search_engine_specifics.proto
@@ -33,8 +33,7 @@ message SearchEngineSpecifics {
   optional int64 date_created = 7;
   // A list of supported input encodings.
   optional string input_encodings = 8;
-  // Whether this entry is shown in the list of default search engines or not.
-  optional bool show_in_default_list = 9;

[Nicolas Zea, 2016/11/14 20:48:10]

Just to be clear, all old versions of Chrome are going to start receiving new
search engines with this value set to false. Presumably that's acceptable, but
just want to make sure.

[ltian, 2016/11/15 19:43:41]

Thanks for letting me know and I think it should be ok because nowhere is
calling this field in the new version of code.

[Peter Kasting, 2016/11/15 19:53:14]

To be clear, he's saying that people running the old code will now start seeing
this set to false if they sync to a profile that is synced to a newer version of
Chrome in another location.

But I think that's true for newly-added engines only?  Which probably means it's
an OK edge case to live with.

+  // ID 9 reserved - previously used by show_in_default_list, now deprecated.
   // The parameterized URL that provides suggestions as the user types.
   optional string suggestions_url = 10;
   // The ID associated with the prepopulate data this search engine comes from.