But what if you need to test the actual web app's performance on a real device?
Chrome Beta – including ChromeOS – now supports native USB discovery of connected devices. Find them under Tools → Inspect Devices menu item, or visit the about:inspect page. There’s no configuration necessary and no need for the adb command line tool or extensions to see all instances of Chrome and WebView on the devices connected to your computer2.
While connected over USB, you can screencast the full viewport content from the device to DevTools. The corresponding icon will be shown next to the Elements tab if the inspected device is able to screencast.
Keyboard and mouse events are also sent from DevTools to your device, so you don't even need to touch it while you're testing your apps.
Posted by Pavel Feldman, Software Engineer and Viewport Teleporter
1 You need to check “Show 'Emulation' view in console drawer” in DevTool’s Settings→ Overrides to enable the emulation features
2 Windows users need to install the USB device drivers to enable device communication