Add some browsers (#6246)

Related: #6165

config/locales/en.yml

@@ -552,12 +552,14 @@ en:
       blackberry: Blackberry
       chrome: Chrome
       edge: Microsoft Edge
+      electron: Electron
       firefox: Firefox
       generic: Unknown browser
       ie: Internet Explorer
       micro_messenger: MicroMessenger
       nokia: Nokia S40 Ovi Browser
       opera: Opera
+      otter: Otter
       phantom_js: PhantomJS
       qq: QQ Browser
       safari: Safari