Remove redundant code to prevent double submission

As mentioned in commit 7f30d0c6, Rails already does it automatically.

app/assets/javascripts/application.js

@@ -60,7 +60,6 @@
 //= require moderator_budget_investments
 //= require moderator_proposal_notifications
 //= require moderator_legislation_proposals
-//= require prevent_double_submission
 //= require gettext
 //= require annotator
 //= require tags
@@ -126,7 +125,6 @@ var initialize_modules = function() {
   App.FoundationExtras.initialize();
   App.LocationChanger.initialize();
   App.CheckAllNone.initialize();
-  App.PreventDoubleSubmission.initialize();
   App.IeAlert.initialize();
   App.AdvancedSearch.initialize();
   App.RegistrationForm.initialize();

app/assets/javascripts/prevent_double_submission.js

@@ -1,48 +0,0 @@
-(function() {
-  "use strict";
-  App.PreventDoubleSubmission = {
-    disable_buttons: function(buttons) {
-      setTimeout(function() {
-        buttons.each(function() {
-          var button, loading, ref;
-          button = $(this);
-          if (!button.hasClass("disabled")) {
-            loading = (ref = button.data("loading")) != null ? ref : "...";
-            button.addClass("disabled").attr("disabled", "disabled");
-            button.data("text", button.val());
-            button.val(loading);
-          }
-        });
-      }, 1);
-    },
-    reset_buttons: function(buttons) {
-      buttons.each(function() {
-        var button, button_text;
-        button = $(this);
-        if (button.hasClass("disabled")) {
-          button_text = button.data("text");
-          button.removeClass("disabled").attr("disabled", null);
-          if (button_text) {
-            button.val(button_text);
-            button.data("text", null);
-          }
-        }
-      });
-    },
-    initialize: function() {
-      $("form").on("submit", function(event) {
-        var buttons;
-        if (!(event.target.id === "new_officing_voter" || event.target.id === "admin_download_emails")) {
-          buttons = $(this).find(":button, :submit");
-          App.PreventDoubleSubmission.disable_buttons(buttons);
-        }
-      }).on("ajax:success", function(event) {
-        var buttons;
-        if (!(event.target.id === "new_officing_voter" || event.target.id === "admin_download_emails")) {
-          buttons = $(this).find(":button, :submit");
-          App.PreventDoubleSubmission.reset_buttons(buttons);
-        }
-      });
-    }
-  };
-}).call(this);

spec/system/comments/debates_spec.rb

@@ -360,11 +360,9 @@ describe "Commenting debates" do
     fill_in "Leave your comment", with: "Testing submit button!"
     click_button "Publish comment"
 
-    # The button"s text should now be "..."
-    # This should be checked before the Ajax request is finished
-    expect(page).not_to have_button "Publish comment"
-
-    expect(page).to have_content("Testing submit button!")
+    expect(page).to have_button "Publish comment", disabled: true
+    expect(page).to have_content "Testing submit button!"
+    expect(page).to have_button "Publish comment", disabled: false
   end
 
   describe "Moderators" do

spec/system/comments/legislation_annotations_spec.rb

@@ -377,11 +377,9 @@ describe "Commenting legislation questions" do
     fill_in "Leave your comment", with: "Testing submit button!"
     click_button "Publish comment"
 
-    # The button's text should now be "..."
-    # This should be checked before the Ajax request is finished
-    expect(page).not_to have_button "Publish comment"
-
-    expect(page).to have_content("Testing submit button!")
+    expect(page).to have_button "Publish comment", disabled: true
+    expect(page).to have_content "Testing submit button!"
+    expect(page).to have_button "Publish comment", disabled: false
   end
 
   describe "Moderators" do

spec/system/comments/legislation_questions_spec.rb

@@ -339,11 +339,9 @@ describe "Commenting legislation questions" do
     fill_in "Leave your answer", with: "Testing submit button!"
     click_button "Publish answer"
 
-    # The button's text should now be "..."
-    # This should be checked before the Ajax request is finished
-    expect(page).not_to have_button "Publish answer"
-
-    expect(page).to have_content("Testing submit button!")
+    expect(page).to have_button "Publish answer", disabled: true
+    expect(page).to have_content "Testing submit button!"
+    expect(page).to have_button "Publish answer", disabled: false
   end
 
   describe "Moderators" do