Chrome Version : 54.0.2824.0 (Official Build) facabd3224aecbcab4bea9daadad31c67488d78c-refs/heads/master@{#410520} (64-bit)
OS: Mac (10.10.5, 10.11.5)

What steps will reproduce the problem?
1. Launch chrome, open NTP and hit Cmd++ to zoom in the page.
2. Click on zoom icon seen in omnibox and then click on ‘Reset’ button.
3. Observe the ‘Reset’ button.

Actual : Unnecessarily ‘Reset’ button is clickable in zoom bubble even when zoom level is 100%.
Expected : ‘Reset’ button should not be clickable when zoom level is 100%.

This is a regression issue broken in M-42, below is the Manual Regression and Narrow Bisect info:
Good build : 42.0.2300.0
Bad build : 42.0.2303.0

Narrow Bisect : 
https://chromium.googlesource.com/chromium/src/+log/c1dcb9c1ba668d4948441d956709ab9747b5c65d..46f415dd3e6c7868cef1eb43a0bdc91085175be0?pretty=fuller&n=10000

Suspecting: 315766 from narrow bisect

Note : This is Mac specific issue and not seen on Windows and Linux OS.
 

Deleted: Actual_zoom_reset.mov 3.5 MB

Actual_zoom_reset.mov 3.5 MB Download

Deleted: Expec_zoom_reset.mov 2.6 MB

Expec_zoom_reset.mov 2.6 MB Download