Revert to the good old days when AssetTag didn't cause anyone problems

actionpack/lib/action_controller/dispatcher.rb

@@ -91,7 +91,6 @@ def reload_application
       run_callbacks :prepare_dispatch
 
       Routing::Routes.reload
-      ActionView::Helpers::AssetTagHelper::AssetTag::Cache.clear
     end
 
     # Cleanup the application by clearing out loaded classes so they can

actionpack/test/controller/dispatcher_test.rb

@@ -32,11 +32,6 @@ def test_reloads_routes_before_dispatch_if_in_loading_mode
     dispatch(false)
   end
 
-  def test_clears_asset_tag_cache_before_dispatch_if_in_loading_mode
-    ActionView::Helpers::AssetTagHelper::AssetTag::Cache.expects(:clear).once
-    dispatch(false)
-  end
-
   def test_leaves_dependencies_after_dispatch_if_not_in_loading_mode
     ActionController::Routing::Routes.expects(:reload).never
     ActiveSupport::Dependencies.expects(:clear).never

actionpack/test/template/asset_tag_helper_test.rb

@@ -38,8 +38,6 @@ def host_with_port() 'localhost' end
     @controller.request = @request
 
     ActionView::Helpers::AssetTagHelper::reset_javascript_include_default
-    AssetTag::Cache.clear
-    AssetCollection::Cache.clear
   end
 
   def teardown