Ember 1.13 upgradation

I'm upgrading the code from Ember 1.0.4 to Ember 1.13. When I'm execute the below code using ember 1.13 I'm getting the error

title: Ember.computed('content.title', 'managedObject.isHome', 'managedObject.finalManagedObject', {
                set: function(name, value) {
                    this.set('content.title', value);
                },
                if (this.get('content.title') !== undefined) {
                    return title;
                }
                if (this.get('managedObject') == Core.rootNode) {
                    return "Home";
                }
                get: function() {
                  return this.get('managedObject.label') || this.get('managedObject.finalManagedObject.displayName');
                }
            }),

I'm getting the below error while execute the code.

Uncaught SyntaxError: Unexpected token this

I got the answer by using the below code:

title: Ember.computed('content.title', 'managedObject', 'managedObject.label', 'managedObject.finalManagedObject.displayName', {
                set: function(titleKey, newTitle) {
                    this.set('content.title', newTitle);
                    if (newTitle !== undefined) {
                        return newTitle;
                    } else if (this.get('managedObject') === Core.rootNode) {
                        return 'Home';
                    }
                    return this.get('managedObject.label') || this.get('managedObject.finalManagedObject.displayName');
                },      
                get: function() {
                    var title = this.get('content.title');
                    if (title !== undefined) {
                        return title;
                    } else if (this.get('managedObject') === Core.rootNode) {
                        return 'Home';
                    }
                    return this.get('managedObject.label') || this.get('managedObject.finalManagedObject.displayName');
                }
            }),

Thanks for your suggestions Rinold Simon and jelhan.