Don't run internal message loop from PrintJob::ControlledWorkerShutdown()

If loops is running, and render is closed, the RenderViewHostImpl that called ControlledWorkerShutdown is going to be destroyed. So RenderViewHostImpl crashes immediately after returning from ControlledWorkerShutdown.

Solution it to use delayed messages instead of nested loop.

BUG=313274
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=249561

Review URL: https://codereview.chromium.org/136733005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249608 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249608