Big update:

* Move all core functions from mains.js to background.js
    * Use message interface for IPCs between main.js, background.js and popup.js
    * Add popup interface :
      	  * safest method to compute masterkey
	  * Direct access to our own gPass server with auto URL and username fill
    * Add some specific menus :
      	  * Access to gPass settings
	  * Allow to disable extension
    * Update gPass icon when a password field has focus and gPass is ready to work

chrome_addon/compat.js

@@ -1,23 +1,23 @@
 /*
-  Copyright (C) 2013-2017 Grégory Soutadé
-  
+  Copyright (C) 2013-2020 Grégory Soutadé
+
   This file is part of gPass.
-  
+
   gPass is free software: you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation, either version 3 of the License, or
   (at your option) any later version.
-  
+
   gPass is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.
-  
+
   You should have received a copy of the GNU General Public License
   along with gPass.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-function getPref(key)
+function get_preference(key)
 {
     // Inspired from https://github.com/akiomik/chrome-storage-promise/
     var promise = new Promise((resolve, reject) => {
@@ -32,14 +32,33 @@ function getPref(key)
     })
 	.then(function (pref) {
 	    if (!pref.hasOwnProperty(key))
-		return default_preferences[key];
+	    {
+		if (default_preferences.hasOwnProperty(key))
+		    return default_preferences[key];
+		else
+		    return null;
+	    }
 	    return pref[key];
 	});
 
     return promise;
 }
 
-function setPref(key, value)
+function set_preference(key, value)
 {
-    chrome.storage.local.set({key:value}, function ok() {});
+    pref = {[key]:value};
+    chrome.storage.local.set(pref, function (result) {
+	if (chrome.runtime.lastError)
+	    alert(chrome.runtime.lastError);
+    });
+}
+
+function delete_preference(key)
+{
+    chrome.storage.local.remove(key);
+}
+
+function send_tab_message(tab_id, parameters, callback)
+{
+    chrome.tabs.sendMessage(tab_id, parameters, {}, callback);
 }