Remove active_support/json/variable was deprecated.
Remove ActiveSupport::Benchmarkable#silence was deprecated.
Remove active_support/testing/pending.rb was deprecated.
Remove :confirm and :disable_with options for ActionView::Helpers::UrlHelper#link_to and #button_to were deprecated.
Remove link_to_function / button_to_function from ActionView::Helpers::JavascriptHelper were deprecated.
Remove :confirm and :disable_with options from ActionView::Helpers::FormTagHelper were deprecated.
Remove action_controller/vendor/html-scanner.rb was deprecated.
Remove ActionController::RecordIdentifier was deprecated.
Remove #sum with a block was deprecated.
Remove ActionView::Template#mime_type was deprecated.
Merge pull request #10814 from kennyj/deprecations_4_1

Remove some deprecation methods / options / files.