GitLab

client_screen.js currently defines a few global functions and a few 'private'
functions that are called in application.js and desktop_connected_view.js

This CL
1. Moves onClientStateChange_, updateStatistics_ into application.js as
   they are called from there and their implementation depends on application.js.
2. Moves declaration of globals clientSession and desktopConnectedView
   into application.js
3. Moves remoting.disconnect into remoting.Application.
4. Moves onResize and onVisibilityChanged into desktop_connected_view.js
5. Removes client_screen.js

BUG=461995

Review URL: https://codereview.chromium.org/952353002

Cr-Commit-Position: refs/heads/master@{#319195}