Tested the issue on chromium with 61.0.3112.113 and on latest stable 61.0.3163.91 using Ubuntu 14.04 with steps mentioned in commet#0.

@Reporter: Could you please upgrade chromium to latest stable and please check the issue on a clean profile without any apps and extensions.

Just to update..

After opening 6 tabs on chromium with a French azerty keyboard layout and pressing Ctrl + - zoomed out the web page as expected.

As Commenter #2 asked, I upgraded to chromium 61.0.3163.91 (on ArchLinux). 
I also started chromium with a completely clean profile as follows:
$ mkdir ~/temp/chromiumtest
$ chromium --user-data-dir=~/temp/chromium

The behavior is still the same as described in my original report.

Thank you for providing more feedback. Adding requester "sc00335628@techmahindra.com" to the cc list and removing "Needs-Feedback" label.

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

Tested the issue on latest chromium build with the steps mentioned below on ubuntu 14.04

1. Opened some 6 tabs on chromium build
2. Pressed Ctl+- simultaneously. Attached screenshot for reference.

@Reporter: Could you please confirm whether you are using French-azerty(m17n) keyboard or anyother.

Thanks!

Thank you for providing more feedback. Adding requester "kebalaji@chromium.org" to the cc list and removing "Needs-Feedback" label.

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

Yes, I confirm I am using a French azerty layout. The key corresponding to the minus sign is the same as the key for the digit 6 (keycode 15 in xev). Ctrl+"-" gives the 6th tab. Ctrl+Shift+"-" yields nothing (that I can immediately see).

To be more precise, my Azerty layout is the OSS variant. See https://cgit.freedesktop.org/xkeyboard-config/tree/symbols/fr for reference.

Tested this issue on Ubuntu 14.04 with chrome #61.0.3163.100 with following Keyboard "Georgian (France AZERTY Tskapo)"

Observations:
1. On pressing Ctrl + - simultaneously, observed screen is zooming out as expected.
2. On pressing Ctrl + 0 simultaneously, screen is zoom In to 100%
3. But on Pressing Ctrl + + simultaneously, screen is not zooms IN as expected

Attaching the screen-cast for reference.

raphael@ Could you confirm this is the issue your are facing and let us know any steps i have missed while reproducing the scenario.

Deleted: 765149.mp4 1.8 MB

	765149.mp4 1.8 MB View Download

Thank you for taking the time to record a sequence. It shows a problem, but unfortunately it is different from mine. As far as I can see, the problem is the keyboard you use, a Georgian one, not a French one.

I have recorded a screencast too, to show my precise problem. 
Here is a commentary of this video:
1. you see my termminal window, showing that I start chromium with a completely empty profile, and that I just reset my keyboard layout with the command `setxkbmap fr oss`.
2. I type <CR>, Chromium opens in a new window. I open seven tabs.
3. While on the 7th tab, I press <CTRL>+<=> (the plus sign is on the "=" key). Zooming in works.
4. While still on the 7th tab, I press <CTRL>+<-> (minus). Chromium switches to the 6th tab (the digit 6 is on the same key as the minus sign). Zooming out is not performed, as expected. 
5. I repeat step 4 from the first tab.
6. I repeat step 4 from the second tab.
7. I repeat step 4 from the sixth tab, showing that on this tab <CTRL>+<-> produces no visible result.

Not shown in the video: 
- the "zooming in" feature also works while holding shift (<CTRL>+<SHIFT>+<=>)
- using <CTRL>+<SHIFT>+<-> produces no visible result

Deleted: vokoscreen-2017-10-12_15-00-29.mp4 665 KB

	vokoscreen-2017-10-12_15-00-29.mp4 665 KB View Download

Thank you for providing more feedback. Adding requester "kkaluri@chromium.org" to the cc list and removing "Needs-Feedback" label.

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

Archiving old bugs that haven't been actively assigned in over 180 days.

If you feel this issue should still be addressed, feel free to reopen it or to file a new issue. Thanks!

Archiving old bugs that haven't been actively assigned in over 180 days.

If you feel this issue should still be addressed, feel free to reopen it or to file a new issue. Thanks!

Archiving old bugs that haven't been actively assigned in over 180 days.

If you feel this issue should still be addressed, feel free to reopen it or to file a new issue. Thanks!