So that it's in the public record: the current drag handle ends 1 DIP above the top of the divider between tabs.  If we move to 34, it will end 0 DIPs above the top, which is maybe OK.  If we move to 32, we'd either need to shorten the divider, increase the height of the frame above the tabs, decrease the drag handle height, or have them overlap; none of these options sounds terribly appealing.

If this is cheap, then let's go ahead and try 34 and try it out. If it is undesirable, we'll go ahead and revert the change.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/0670e881945cb0c5f3c49ab55f7f96007472c0e3

commit 0670e881945cb0c5f3c49ab55f7f96007472c0e3
Author: Allen Bauer <kylixrd@chromium.org>
Date: Fri Jul 13 13:03:39 2018

[Refresh] Reduce the height of the tabs from 36 to 34.

Inactive tab hit-testing overlap regions is now calculated to be 1 dip
above the top of the tab separator.

Bug:  859204 
Change-Id: Idbd92f9209ff2bbcd5516f26d1acfbd0b83ae563
Reviewed-on: https://chromium-review.googlesource.com/1135726
Reviewed-by: Peter Kasting <pkasting@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Allen Bauer <kylixrd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574889}
[modify] https://crrev.com/0670e881945cb0c5f3c49ab55f7f96007472c0e3/ash/public/cpp/ash_layout_constants.cc
[modify] https://crrev.com/0670e881945cb0c5f3c49ab55f7f96007472c0e3/chrome/browser/ui/layout_constants.cc
[modify] https://crrev.com/0670e881945cb0c5f3c49ab55f7f96007472c0e3/chrome/browser/ui/views/tabs/tab_strip.cc