Get rid of tracked field

It makes a debugging slightly easier, but is not necessary, and is a waste of resources.

lib/gitlab/background_migration/populate_untracked_uploads.rb

@@ -50,14 +50,10 @@ module Gitlab
           }
         ].freeze
 
-        scope :untracked, -> { where(tracked: false) }
-
         def ensure_tracked!
-          return if persisted? && tracked?
-
           add_to_uploads unless in_uploads?
 
-          mark_as_tracked
+          delete
         end
 
         def in_uploads?
@@ -79,10 +75,6 @@ module Gitlab
           )
         end
 
-        def mark_as_tracked
-          update!(tracked: true)
-        end
-
         def upload_path
           # UntrackedFile#path is absolute, but Upload#path depends on uploader
           if uploader == 'FileUploader'
@@ -197,7 +189,7 @@ module Gitlab
       def perform(start_id, end_id)
         return unless migrate?
 
-        files = UntrackedFile.untracked.where(id: start_id..end_id)
+        files = UntrackedFile.where(id: start_id..end_id)
         files.each do |untracked_file|
           begin
             untracked_file.ensure_tracked!
@@ -220,7 +212,7 @@ module Gitlab
       end
 
       def drop_temp_table_if_finished
-        UntrackedFile.connection.drop_table(:untracked_files_for_uploads) if UntrackedFile.untracked.empty?
+        UntrackedFile.connection.drop_table(:untracked_files_for_uploads) if UntrackedFile.all.empty?
       end
     end
   end

lib/gitlab/background_migration/prepare_untracked_uploads.rb

@@ -42,10 +42,8 @@ module Gitlab
         unless UntrackedFile.connection.table_exists?(:untracked_files_for_uploads)
           UntrackedFile.connection.create_table :untracked_files_for_uploads do |t|
             t.string :path, limit: 600, null: false
-            t.boolean :tracked, default: false, null: false
             t.timestamps_with_timezone null: false
             t.index :path, unique: true
-            t.index :tracked
           end
         end
       end

spec/lib/gitlab/background_migration/populate_untracked_uploads_spec.rb

@@ -54,12 +54,12 @@ describe Gitlab::BackgroundMigration::PopulateUntrackedUploads, :migration, :sid
       expect(appearance.uploads.count).to eq(2)
     end
 
-    it 'sets all added or confirmed tracked files to tracked' do
+    it 'deletes rows after processing them' do
       expect(subject).to receive(:drop_temp_table_if_finished) # Don't drop the table so we can look at it
 
       expect do
         subject.perform(1, 1000)
-      end.to change { untracked_files_for_uploads.where(tracked: true).count }.from(0).to(8)
+      end.to change { untracked_files_for_uploads.count }.from(8).to(0)
     end
 
     it 'does not create duplicate uploads of already tracked files' do
@@ -85,7 +85,7 @@ describe Gitlab::BackgroundMigration::PopulateUntrackedUploads, :migration, :sid
       expect(project2.uploads.count).to eq(0)
 
       # Only 4 have been either confirmed or added to uploads
-      expect(untracked_files_for_uploads.where(tracked: true).count).to eq(4)
+      expect(untracked_files_for_uploads.count).to eq(4)
     end
 
     it 'uses the start and end batch ids [only 2nd half]' do
@@ -103,7 +103,7 @@ describe Gitlab::BackgroundMigration::PopulateUntrackedUploads, :migration, :sid
       expect(project2.uploads.count).to eq(2)
 
       # Only 4 have been either confirmed or added to uploads
-      expect(untracked_files_for_uploads.where(tracked: true).count).to eq(4)
+      expect(untracked_files_for_uploads.count).to eq(4)
     end
 
     it 'does not drop the temporary tracking table after processing the batch, if there are still untracked rows' do
@@ -254,18 +254,6 @@ describe Gitlab::BackgroundMigration::PopulateUntrackedUploads::UntrackedFile do
     end
   end
 
-  describe '#mark_as_tracked' do
-    it 'saves the record with tracked set to true' do
-      untracked_file = create_untracked_file("/-/system/appearance/logo/1/some_logo.jpg")
-
-      expect do
-        untracked_file.mark_as_tracked
-      end.to change { untracked_file.tracked }.from(false).to(true)
-
-      expect(untracked_file.persisted?).to be_truthy
-    end
-  end
-
   describe '#upload_path' do
     def assert_upload_path(file_path, expected_upload_path)
       untracked_file = create_untracked_file(file_path)