UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.132 Safari/537.36

Steps to reproduce the problem:
1. Open any number of tabs greater than one.
2. Select the text in the address bar in one of the tabs, e.g. in the middle
3. Press Option+Shift+Left or Option+Shift+Right

Additionally,

1. (same)
2. Open a page that has a textarea field.
3. (same)

What is the expected behavior?
For left, the previous word is selected. E.g. on a URL like http://site.com/word if the cursor is at the end of the URL, Option+Shift+Left should select "word".

For right, the next word is selected. If on http://site.com/word and the cursor is in between / and w, pressing Option+Shift+Right should select "word".

This is standard OSX text selection behavior that can be seen everywhere in the system, e.g. on TextEdit.app, the Finder window search bar, and generally everywhere there is text to edit.

What went wrong?
For left, all tabs left of the currently active tab are closed.

For right, all tabs right of the currently active tab are closed.

Did this work before? Yes 62

Chrome version: 63.0.3239.132  Channel: stable
OS Version: OS X 10.13.1
Flash Version: 

This has caused me to accidentally close tabs ever since I updated. It's quite annoying. I'm considering briefly switching to Firefox until the problem is resolved.

This is only relevant to Mac OS X, since Option+Left and Option+Right and, by extension, Option+Shift+Left and Option+Shift+Right are system-wide text editing shortcuts only on Mac OS X, and to my knowledge on no other systems.