Issue 1670 - Removed "Hide placeholders" option from the UI (Firefox)

lib/ui.js

Index: lib/ui.js
===================================================================
--- a/lib/ui.js
+++ b/lib/ui.js
@@ -504,6 +504,11 @@
     {
       Prefs.currentVersion = addonVersion;
       this.addSubscription(window, prevVersion);
+
+      // The "Hide placeholders" option has been removed from the UI in 2.6.6.3881
+      // So we reset the option for users updating from older versions.
+      if (prevVersion && Services.vc.compare(prevVersion, "2.6.6.3881") < 0)
+        Prefs.fastcollapse = false;
     }
   },
 
@@ -1532,7 +1537,6 @@
 
     setChecked(prefix + "disabled", !Prefs.enabled);
     setChecked(prefix + "frameobjects", Prefs.frameobjects);
-    setChecked(prefix + "slowcollapse", !Prefs.fastcollapse);
     setChecked(prefix + "savestats", Prefs.savestats);
 
     let {defaultToolbarPosition, statusbarPosition} = require("appSupport");
@@ -1941,7 +1945,6 @@
   ["abp-command-togglesitewhitelist", "command", function() { UI.toggleFilter(siteWhitelist); }],
   ["abp-command-togglepagewhitelist", "command", function() { UI.toggleFilter(pageWhitelist); }],
   ["abp-command-toggleobjtabs", "command", UI.togglePref.bind(UI, "frameobjects")],
-  ["abp-command-togglecollapse", "command", UI.togglePref.bind(UI, "fastcollapse")],
   ["abp-command-togglesavestats", "command", UI.toggleSaveStats.bind(UI)],
   ["abp-command-togglesync", "command", UI.toggleSync.bind(UI)],
   ["abp-command-toggleshowintoolbar", "command", UI.toggleToolbarIcon.bind(UI)],