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

components/sync/protocol/search_engine_specifics.proto

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Sync protocol datatype extension for custom search engines.
 
 // Update proto_value_conversions{.h,.cc,_unittest.cc} if you change
 // any fields in this file.
 
 syntax = "proto2";
@@ skipping 15 matching lines @@
   // A flag signifying whether it is safe to automatically modify this search
   // engine entry or not.
   optional bool safe_for_autoreplace = 5;
   // The URL to the OSD file this search engine entry came from.
   optional string originating_url = 6;
   // The date this search engine entry was created. A UTC timestamp with units
   // in microseconds.
   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.
   // Set to zero if it was not prepopulated.
   optional int32 prepopulate_id = 11;
   // DEPRECATED: Whether to autogenerate a keyword for the search engine or not.
   // Do not write to this field in the future.  We preserve this for now so we
   // can read the field in order to migrate existing data that sets this bit.
   optional bool autogenerate_keyword = 12;
   // ID 13 reserved - previously used by |logo_id|, now deprecated.
   // Obsolete field. This used to represent whether or not this search engine
   // entry was created automatically by an administrator via group policy. This
   // notion no longer exists amongst synced search engines as we do not want to
   // sync managed search engines.
   // optional bool deprecated_created_by_policy = 14;

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

Prefer deprecating in this fashion: rename to deprecated_created_by_policy, and
comment out. This helps preserve knowledge about what kind of field this used to
be, and also makes it clearer that a field was there before (your comment above
looks almost like it's a comment about suggestions_url)

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

Done.

   // The parameterized URL that is used for Instant results.
   optional string instant_url = 15;
   // ID 16 reserved - previously used by |id|, now deprecated.
   // The last time this entry was modified by a user. A UTC timestamp with units
   // in microseconds.
   optional int64 last_modified = 17;
   // The primary identifier of this search engine entry for Sync.
   optional string sync_guid = 18;
   // A list of URL patterns that can be used, in addition to |url| and
   // |instant_url|, to extract search terms from a URL.
   repeated string alternate_urls = 19;
   // Parameter that, if present in a search URL, indicates that Chrome should
   // perform search terms replacement in the omnibox.
   optional string search_terms_replacement_key = 20;
   // The parameterized URL that provides image results according to the image
   // content or image URL provided by user.
   optional string image_url = 21;
 
   // The following post_params are comma-separated lists used to specify the
   // post parameters for the corresponding search URL.
   optional string search_url_post_params = 22;
   optional string suggestions_url_post_params = 23;
   optional string instant_url_post_params = 24;
   optional string image_url_post_params = 25;
 
   // The parameterized URL for a search provider specified new tab page.
   optional string new_tab_url = 26;
 }