The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/90ac0d3da58ffe49a74ddf0bca158b4961cf1931

commit 90ac0d3da58ffe49a74ddf0bca158b4961cf1931
Author: peterlaurens <peterlaurens@chromium.org>
Date: Thu Jun 08 21:13:39 2017

Perf metric tracking the wallclock time it takes to show a new tab page.

BUG= 724682 

Review-Url: https://codereview.chromium.org/2895013002
Cr-Commit-Position: refs/heads/master@{#478086}

[modify] https://crrev.com/90ac0d3da58ffe49a74ddf0bca158b4961cf1931/ios/chrome/browser/ui/browser_view_controller.mm
[modify] https://crrev.com/90ac0d3da58ffe49a74ddf0bca158b4961cf1931/ios/chrome/browser/ui/stack_view/stack_view_controller.mm
[modify] https://crrev.com/90ac0d3da58ffe49a74ddf0bca158b4961cf1931/tools/metrics/histograms/histograms.xml

Please note there is typo in metric "Toolbar.TabSwitcher.NewIncognitoTabPresentationDurationn", double n at the end instead of single n.
https://drive.google.com/file/d/0B-xmXLQhjeKuNXhlRkROZHcxWDA/view

Also I am not seeing any Histogram when opening a new tab using Menu --> New Tab.

Steps I followed:

Launch Chrome
Tap Menu --> New Tab few times
Tap Menu --> New Incognito tab few times.
Navigate to about://histograms
Find In Page for "Toolbar.Menu"

No results found.

Please let me know if I am missing anything.

Thanks! I will take a look

Thanks Srikanth, I can reproduce the issue and have a CL up here:

https://codereview.chromium.org/2952433002/

Thanks for your help!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9f1b6e0775d4a97df66d39197df9c6a01a41539b

commit 9f1b6e0775d4a97df66d39197df9c6a01a41539b
Author: peterlaurens <peterlaurens@chromium.org>
Date: Thu Jun 22 17:46:45 2017

Fix tab presentation metrics

BUG= 724682 

Review-Url: https://codereview.chromium.org/2952433002
Cr-Commit-Position: refs/heads/master@{#481590}

[modify] https://crrev.com/9f1b6e0775d4a97df66d39197df9c6a01a41539b/ios/chrome/browser/ui/browser_view_controller.mm
[modify] https://crrev.com/9f1b6e0775d4a97df66d39197df9c6a01a41539b/ios/chrome/browser/ui/stack_view/stack_view_controller.mm

Type in Metric is now fixed. And all other Metrics are recorded correctly.

Verified in M61.0.3141.0 canary
Device: iPhone6 plus
iOS: 10.3.2