This creates a task manager provider that tracks the life and death of
RenderProcessHosts. This is useful because it will track processes that
are otherwise not included in the current task manager. An example of
this is the NTP which has a service worker that lives beyond navigating
away from the NTP. With this you can accurately see when the
termination of the RenderProcessHost that is running this service
worker.

This version is requires the commandline flag of "--task-manager-show-extra-renderers" to be used.

BUG=716609

Review-Url: https://codereview.chromium.org/2988453002
Cr-Commit-Position: refs/heads/master@{#491420}
9 files changed