GitLab

Replace PrintMsg_ClosePrintPreviewDialog and
PrintMsg_PrintForSystemDialog IPC messages with new Mojo methods.

Bug: 1008939
Test: Print a webpage and PDF
Change-Id: I59dd3f50f01c04debe3cb0ebd51062bc6cf597be
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1829467Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Sean Kau <skau@chromium.org>
Commit-Queue: Jesse Schettler <jschettler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705747}