90fb15a7e5
First, this change adds a column to the downloads table specifying whether a download should be displayed in the system downloads UI. It adds a public method to set this parameter when requesting a download, and a hidden method to filter queries based on this paramter (such filtering could be made public later, but it's not strictly necessary right now). Second, this change adds support for restarting a completed/failed download as a hidden method on DownloadManager. Currently it only works from the download manager's process - it'll be used by the new download manager UI. Change-Id: I15eda1a6e3717d1ce947a810b25ad3540cce809e