FYI, some more info about my machine:

$ uname -a
Linux argon 4.8.0-44-generic #47-Ubuntu SMP Wed Mar 22 14:27:57 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

$ cat /etc/lsb-release 
DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=16.10
DISTRIB_CODENAME=yakkety
DISTRIB_DESCRIPTION="Ubuntu 16.10"

Oshima: Let me know if you need more info, like maybe from about:gpu.

Linux chrome reads gtk-xft-dpi property to determine the scale, and I'm wondering if something has changed on Ubuntu side. Can you add

Xft.dpi:192

to ~/.Xresources and see if it fixes/changes behavior?

yes, setting it helps (it also fixed small gui of the latest firefox).

please note, that chrome stopped to take dpi setting from x11 completely - my x11 session is started with explicit definition with the command line argument "-dpi 120", so it is a bit disappointing that this setting is not working anymore.

I would like to chime in that I am also expressing this regression on Fedora 25 with GNOME 3. Only when I use --force-device-scale-factor 2 could I cajole Chrome into launching with the correct scaling on my display. I believe this is a regression with the latest Chrome unstable version, as it was not a problem when I first installed Chrome on this machine about a week ago.

Note that as per the default on Fedora 25, I am running GNOME in a Wayland session, though as I understand it Chrome would have been launched under XWayland?

Chrome version:
Google Chrome	59.0.3053.3 (Official Build) dev (64-bit)
Revision	d06aedb601e668067132026a8f14fe0179697b50-refs/branch-heads/3053@{#4}
OS	Linux
JavaScript	V8 5.9.97
Flash	25.0.0.143 /home/[redacted]/.config/google-chrome-unstable/PepperFlash/25.0.0.143/libpepflashplayer.so
User Agent	Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3053.3 Safari/537.36
Command Line	/usr/bin/google-chrome-unstable --user-data-dir=/home/[redacted]/.config/google-chrome-unstable --force-device-scale-factor=2 --flag-switches-begin --flag-switches-end
Executable Path	/opt/google/chrome-unstable/google-chrome-unstable

Kernel:
$ uname -a
Linux [redacted] 4.10.6-200.fc25.x86_64 #1 SMP Mon Mar 27 14:06:23 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux

GNOME:
$ gnome-shell --version
GNOME Shell 3.22.3

OS:
$ cat /etc/os-release 
NAME=Fedora
VERSION="25 (Workstation Edition)"
ID=fedora
VERSION_ID=25
PRETTY_NAME="Fedora 25 (Workstation Edition)"
ANSI_COLOR="0;34"
CPE_NAME="cpe:/o:fedoraproject:fedora:25"
HOME_URL="https://fedoraproject.org/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Fedora"
REDHAT_BUGZILLA_PRODUCT_VERSION=25
REDHAT_SUPPORT_PRODUCT="Fedora"
REDHAT_SUPPORT_PRODUCT_VERSION=25
PRIVACY_POLICY_URL=https://fedoraproject.org/wiki/Legal:PrivacyPolicy
VARIANT="Workstation Edition"
VARIANT_ID=workstation

I'm also experiencing this. (This is not the first time this has regressed either.)

I'm very sure it's Chrome dev (59) specific. I keep Chromium stable (57) installed side-by-side and it's scaled appropriately still.

I also run under a Wayland session, but I know Chrom(e|ium) run under XWayland and it was no different under the X session anyway.

$ uname -a
Linux pixel 4.10.8-7-ph #1 SMP Sun Apr 9 00:01:06 PDT 2017 x86_64 GNU/Linux

$ cat /etc/os-release
NAME="Arch Linux"
PRETTY_NAME="Arch Linux"
ID=arch
ID_LIKE=archlinux
ANSI_COLOR="0;36"
HOME_URL="https://www.archlinux.org/"
SUPPORT_URL="https://bbs.archlinux.org/"
BUG_REPORT_URL="https://bugs.archlinux.org/"

$ gnome-shell --version
GNOME Shell 3.24.0

$ pacman -Q | grep gnome-desktop
gnome-desktop 1:3.24.0-1

$ pacman -Q | grep gnome-session
gnome-session 3.24.0+1+g076d2e7e-1

$ cat ~/.Xresources
cat: /home/cole/.Xresources: No such file or directory

chrome://version

Google Chrome	59.0.3067.0 (Official Build) dev (64-bit)
Revision	e2ed4b4539b7a50d8be892e4437897b18c181c91-refs/heads/master@{#463157}
OS	Linux
JavaScript	V8 5.9.195
Flash	25.0.0.152 /home/cole/.config/google-chrome-unstable/PepperFlash/25.0.0.152/libpepflashplayer.so
User Agent	Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/59.0.3067.0 Safari/537.36
Command Line	/opt/google/chrome-unstable/google-chrome-unstable --user-data-dir=/home/cole/.config/google-chrome-unstable --flag-switches-begin --enable-features=MaterialDesignExtensions,MaterialDesignSettings --flag-switches-end
Executable Path	/opt/google/chrome-unstable/google-chrome-unstable
Profile Path	/home/cole/.config/google-chrome-unstable/Default

 Issue 709979  has been merged into this issue.

This regression is now present in Chrome Beta.

Version 59.0.3071.29 (Official Build) beta (64-bit)

Actually, this may be a side effect of switching to gtk3 lib.  crbug.com/79722 .

thomasanderson@, linux chrome is currently using gtk-xft-dpi to decide the scale factor here:

https://cs.chromium.org/chromium/src/chrome/browser/ui/libgtkui/gtk_ui.cc?rcl=d4c124aa6f93deabb5415b6463d8ac6c362e0eab&l=325

and I'm wondering if there is a change in gtk3 how to handle ui scaling. Can you take a look?

https://codereview.chromium.org/2852593002/ should fix the issue