Create ghacks-clear-57-[changes-only].js

https://github.com/ghacksuserjs/ghacks-user.js/issues/276
https://github.com/ghacksuserjs/ghacks-user.js/wiki/1.6-Bulk-Pref-Resetting-%5BScratchpad%5D

scratchpad-scripts/ghacks-clear-57-[changes-only].js

@@ -0,0 +1,54 @@
+
+(function() {
+  let ops = [
+    '_user.js.parrot',
+    /* --- 57-alpha --- */
+    /* commented out */
+    'browser.storageManager.enabled',
+    'dom.storageManager.enabled',
+    /* removed from the user.js */
+    'browser.search.geoip.timeout',
+    'geo.wifi.xhr.timeout',
+    'gfx.layerscope.enabled',
+    'media.webspeech.recognition.enable',
+    /* moved to RFP ALTERNATIVES */
+    'dom.w3c_touch_events.enabled',
+    'media.video_stats.enabled',
+    /* moved to DEPRECATED/REMOVED */
+    'browser.bookmarks.showRecentlyBookmarked',
+    'browser.casting.enabled',
+    'devtools.webide.autoinstallFxdtAdapters',
+    'media.eme.chromium-api.enabled',
+    'social.directories',
+    'social.enabled',
+    'social.remote-install.enabled',
+    'social.share.activationPanelEnabled',
+    'social.shareDirectory',
+    'social.toast-notifications.enabled',
+    'social.whitelist'
+  ]
+
+  if("undefined" === typeof(Services)) {
+    alert("about:config needs to be the active tab!");
+    return;
+  }
+  
+  let c = 0;
+  for (let i = 0, len = ops.length; i < len; i++) {
+    if (Services.prefs.prefHasUserValue(ops[i])) {   
+      Services.prefs.clearUserPref(ops[i]);
+      if (!Services.prefs.prefHasUserValue(ops[i])) {
+        console.log("reset", ops[i]);
+        c++;
+      } else { console.log("failed to reset", ops[i]); }
+    }
+  }
+  
+  focus();
+  
+  let d = (c==1) ? " pref" : " prefs";
+  if (c > 0) {
+    alert("successfully reset " + c + d + "\n\nfor details check the Browser Console (Ctrl+Shift+J)");
+  } else { alert("nothing to reset"); }
+  
+})();