Extract the remote calls into the class (2/2)

Extract the remote calls into the class (2/2)

Extract the remove call functions into the class, to use them to control not only Files.app window but also windows of other app (eg. video player, audio player and so on).

BUG=405415
TEST=browser_test passes
R=hirono@chromium.org

Review URL: https://codereview.chromium.org/640623002

Cr-Commit-Position: refs/heads/master@{#298937}