Chrome Version: 51.0.2704.7 (Official Build)a8bebc2b0cd3e3018b7c9f6ac698f04dd226abba-refs/branch-heads/2704@{#48} 32/64-bit.
OS: All(Win 7-Aero enabled)

What steps will reproduce the problem?
1. Launch chrome, go to NTP, open 'DevTools' and press 'Esc' key to open console drawer window.
2. Go to 'Sensors' tab from open tab menu list and select 'Force enabled' option from 'Touch' drop-down list.
3. Now double tap/click on NTP(NTP will zoom in) and again double tap/click on NTP and observe.
4. Close the DevTools window and reload the NTP and observe.


Actual:
After Step 3: NTP doesn't zoom out on double tap/click on it. 
After Step 4: NTP doesn't change to default zoom level on reloading the page.

Expected:
After Step 3: NTP should zoom out on double tap/click on it.
After Step 4: NTP should change to default zoom level on reloading the page.

This is a regression issue, broken in M-51 series, below is bisect info.

Manual regression range:
Good: 50.0.2661.0 
Bad: 51.0.2662.0 

Narrow bisect:
https://chromium.googlesource.com/chromium/src/+log/fa369d7c9fe9d5f5ae07b741f7a11c3a19a76c98..09976d9a04c027ea02aef1eec91fb3938ed7eba7?pretty=fuller&n=50

Suspecting: r378125

Kindly review the attached screen-cast for reference.
 

Deleted: Actual_Screenshot.mp4 1.0 MB

Actual_Screenshot.mp4 1.0 MB Download