| Index: lib/io.js | 
| diff --git a/lib/io.js b/lib/io.js | 
| index 6a07389c6f2eafec04176b87cf46de1cacbd17c6..4b352d0036d40e65157666ba728ddd84e2420101 100644 | 
| --- a/lib/io.js | 
| +++ b/lib/io.js | 
| @@ -15,6 +15,8 @@ | 
| * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>. | 
| */ | 
|  | 
| +"use strict"; | 
| + | 
| const keyPrefix = "file:"; | 
|  | 
| function fileToKey(file) | 
| @@ -26,7 +28,7 @@ function loadFile(file, successCallback, errorCallback) | 
| { | 
| let key = fileToKey(file); | 
|  | 
| -  ext.storage.get([key], function(items) | 
| +  ext.storage.get([key], items => | 
| { | 
| let entry = items[key]; | 
|  | 
| @@ -51,12 +53,9 @@ function saveFile(file, data, callback) | 
|  | 
| exports.IO = | 
| { | 
| -  resolveFilePath: function(path) | 
| -  { | 
| -    return new FakeFile(path); | 
| -  }, | 
| +  resolveFilePath(path) { return new FakeFile(path); }, | 
|  | 
| -  readFromFile: function(file, listener, callback) | 
| +  readFromFile(file, listener, callback) | 
| { | 
| function onLoaded(entry) | 
| { | 
| @@ -70,12 +69,12 @@ exports.IO = | 
| loadFile(file, onLoaded, callback); | 
| }, | 
|  | 
| -  writeToFile: function(file, data, callback) | 
| +  writeToFile(file, data, callback) | 
| { | 
| saveFile(file, data, callback); | 
| }, | 
|  | 
| -  copyFile: function(fromFile, toFile, callback) | 
| +  copyFile(fromFile, toFile, callback) | 
| { | 
| function onLoaded(entry) | 
| { | 
| @@ -85,11 +84,11 @@ exports.IO = | 
| loadFile(fromFile, onLoaded, callback); | 
| }, | 
|  | 
| -  renameFile: function(fromFile, newName, callback) | 
| +  renameFile(fromFile, newName, callback) | 
| { | 
| function onLoaded(entry) | 
| { | 
| -      ext.storage.remove(fileToKey(fromFile), function() | 
| +      ext.storage.remove(fileToKey(fromFile), () => | 
| { | 
| ext.storage.set(keyPrefix + newName, entry, callback); | 
| }); | 
| @@ -98,12 +97,12 @@ exports.IO = | 
| loadFile(fromFile, onLoaded, callback); | 
| }, | 
|  | 
| -  removeFile: function(file, callback) | 
| +  removeFile(file, callback) | 
| { | 
| ext.storage.remove(fileToKey(file), callback); | 
| }, | 
|  | 
| -  statFile: function(file, callback) | 
| +  statFile(file, callback) | 
| { | 
| function onLoaded(entry) | 
| { | 
|  |