Move all "checks" under `GitLab::Checks`.

- https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/4892#note_12892160
- This is more consistent.

app/services/merge_requests/refresh_service.rb

@@ -49,7 +49,7 @@ module MergeRequests
     end
 
     def force_push?
-      Gitlab::ForcePushCheck.force_push?(@project, @oldrev, @newrev)
+      Gitlab::Checks::ForcePush.force_push?(@project, @oldrev, @newrev)
     end
 
     # Refresh merge request diff if we push to source or target branch of merge request

lib/gitlab/git_access/change_access_check.rb → lib/gitlab/checks/change_access.rb

 module Gitlab
-  class GitAccess
-    class ChangeAccessCheck
+  module Checks
+    class ChangeAccess
       include PathLocksHelper
-
       attr_reader :user_access, :project
 
       def initialize(change, user_access:, project:)
@@ -81,7 +80,7 @@ module Gitlab
       end
 
       def forced_push?
-        Gitlab::ForcePushCheck.force_push?(@project, @oldrev, @newrev)
+        Gitlab::Checks::ForcePush.force_push?(@project, @oldrev, @newrev)
       end
 
       def matching_merge_request?

lib/gitlab/checks/force_push.rb

+module Gitlab
+  module Checks
+    class ForcePush
+      def self.force_push?(project, oldrev, newrev)
+        return false if project.empty_repo?
+
+        # Created or deleted branch
+        if Gitlab::Git.blank_ref?(oldrev) || Gitlab::Git.blank_ref?(newrev)
+          false
+        else
+          missed_refs, _ = Gitlab::Popen.popen(%W(#{Gitlab.config.git.bin_path} --git-dir=#{project.repository.path_to_repo} rev-list #{oldrev} ^#{newrev}))
+          missed_refs.split("\n").size > 0
+        end
+      end
+    end
+  end
+end

lib/gitlab/force_push_check.rb

-module Gitlab
-  class ForcePushCheck
-    def self.force_push?(project, oldrev, newrev)
-      return false if project.empty_repo?
-
-      # Created or deleted branch
-      if Gitlab::Git.blank_ref?(oldrev) || Gitlab::Git.blank_ref?(newrev)
-        false
-      else
-        missed_refs, _ = Gitlab::Popen.popen(%W(#{Gitlab.config.git.bin_path} --git-dir=#{project.repository.path_to_repo} rev-list #{oldrev} ^#{newrev}))
-        missed_refs.split("\n").size > 0
-      end
-    end
-  end
-end

lib/gitlab/git_access.rb

@@ -111,7 +111,7 @@ module Gitlab
     end
 
     def change_access_check(change)
-      ChangeAccessCheck.new(change, user_access: user_access, project: project).exec
+      Checks::ChangeAccess.new(change, user_access: user_access, project: project).exec
     end
 
     def forced_push?(oldrev, newrev)