GitLab

Added recording of user actions for all context menu actions:
 - open context menu
 - open item in new tab
 - open item in new window
 - open item in an incognito tab
 - download item
 - remove item
 - undo removal of item

BUG=713145

Review-Url: https://codereview.chromium.org/2831113002
Cr-Commit-Position: refs/heads/master@{#466932}