Disable the NtMapViewOfSection hook when printing is initiated

Due to an issue with printing drivers possibly loading third-party DLLs
that mustn't be blocked, initiating a printing operation now disables
the hook in chrome_elf for the remainder of the process' lifetime.

This is a short term solution to allow us to ship third-party blocking.

Bug: 809738, 892294
Change-Id: I0b583197c2b619226e5a4a05836451b9f30eb133
Reviewed-on: https://chromium-review.googlesource.com/c/1312166
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Patrick Monette <pmonette@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610672}
19 files changed