Remove unnecessary `respond_to?(:indexes)` checking

Currently all adapters (postgresql, mysql2, sqlite3, oracle-enhanced,
and sqlserver) implemented `indexes` and schema dumper expects
implemented `indexes`.

https://github.com/rails/rails/blob/v5.0.0/activerecord/lib/active_record/schema_dumper.rb#L208

Therefore `respond_to?(:indexes)` checking is unnecessary.

1 files changed, 0 insertions, 4 deletions

diff --git a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
index 29520ed9c8..2d6bf5e874 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/schema_statements.rb
@@ -1199,10 +1199,6 @@ module ActiveRecord
         def index_name_for_remove(table_name, options = {})
           return options[:name] if can_remove_index_by_name?(options)
 
-          # if the adapter doesn't support the indexes call the best we can do
-          # is return the default index name for the options provided
-          return index_name(table_name, options) unless respond_to?(:indexes)
-
           checks = []
 
           if options.is_a?(Hash)