Didn't repro for me on Mac OS 10.12.5, chrome version: 61.0.3156.0. Looks to be Linux specific.

Able to reproduce this issue on Ubuntu 14.04 using chrome latest dev #61.0.3157.0. This issue is only able to reproduce if the screen resolution is ≤1366*768. 

Bisect Information:
---------------------
You are probably looking for a change made after 485930 (known good), but no later than 485935 (first known bad).

Change Log URL: 
https://chromium.googlesource.com/chromium/src/+log/f8059bbc87dff273b3445a33c8e57c91d089ad31..474df01407e5d38c85364ae4d1709b8d9af16f16

From the above change log suspecting below change
https://chromium.googlesource.com/chromium/src/+/3b4c6874fc78f6e2da1e1578c2bc5cf5a78348c4

pfeldman@ - Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38

commit cc099f72c9fe6f67590e70b2956e27a7b5e7ac38
Author: Pavel Feldman <pfeldman@chromium.org>
Date: Thu Jul 20 23:09:00 2017

DevTools: do not set visible size while emulating in case of device mode.

Bug:  742990 
Change-Id: Ibe303f5e0f5a94015adad2b0d90de963b25d61fb
TBR: tsepez (removing params from ipc message)
Reviewed-on: https://chromium-review.googlesource.com/572222
Commit-Queue: Pavel Feldman <pfeldman@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488472}
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/browser/devtools/protocol/emulation_handler.cc
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/browser/devtools/protocol/emulation_handler.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/common/view_messages.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/renderer/devtools/render_widget_screen_metrics_emulator.cc
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/renderer/devtools/render_widget_screen_metrics_emulator.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/renderer/external_popup_menu.cc
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/renderer/external_popup_menu.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/renderer/render_widget.cc
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/content/renderer/render_widget_unittest.cc
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/events/WebInputEventConversion.cpp
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/events/WebInputEventConversionTest.cpp
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/exported/WebViewTest.cpp
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/frame/LocalFrameView.cpp
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/frame/LocalFrameView.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/frame/WebLocalFrameBase.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/inspector/DevToolsEmulator.cpp
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/core/inspector/browser_protocol.json
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/devtools/front_end/emulation/DeviceModeModel.js
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/web/WebLocalFrameImpl.cpp
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/Source/web/WebLocalFrameImpl.h
[modify] https://crrev.com/cc099f72c9fe6f67590e70b2956e27a7b5e7ac38/third_party/WebKit/public/web/WebDeviceEmulationParams.h

Running on Canary for 3+ days with no issue.

Your change meets the bar and is auto-approved for M61. Please go ahead and merge the CL to branch 3163 manually. Please contact milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), ketakid @(ChromeOS), govind@(Desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Pls merge you change to M61 branch 3163 by 5:00 PM today, Wednesday if possible so we can take it in for next week M61 last dev release. Thank you.

Turns out branch was cut after it.