Use app name as desktop name by default.

atom/browser/lib/init.coffee

@@ -81,7 +81,7 @@ setImmediate ->
   if packageJson.desktopName?
     app.setDesktopName packageJson.desktopName
   else 
-    app.setDesktopName 'atom-shell.desktop'
+    app.setDesktopName '#{app.getName()}.desktop'
 
   # Load the chrome extension support.
   require './chrome-extension.js'

docs/api/browser-window.md

@@ -497,7 +497,7 @@ Change to indeterminate mode when progress > 1.
 
 On Linux platform, only supports Unity desktop environment, you need to specify
 the `*.desktop` file name to `desktopName` field in `package.json`. By default,
-it will assume `atom-shell.desktop`.
+it will assume `app.getName().desktop`.
 
 ## Class: WebContents