Add flag to enable reader mode to chrome://flags.

This has the same effect as running chrome with --enable-dom-distiller
from the command line.

Bug: 925965
Change-Id: Ic2438c3a9a4b8db16271eb2483c919c9e3817235
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1566680
Commit-Queue: Aran Gilman <gilmanmh@google.com>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#651976}
5 files changed