Application Version (from "Chrome Settings > About Chrome"): 51.0.2690.0
Android Build Number (from "Android Settings > About Phone/Tablet"): MHC19M
Device: Nexus 5x
Is Merge Tabs and Apps enabled: Yes

Steps to reproduce: 

0) Enable Flywheel in Settings, enable Previews for cellular networks in chrome://flags, and disable WiFi - so all HTTP pages will get Previews.

1) Use latest version of GSA app (which uses Chrome Plate) to do a search for, e.g., "tessellation"

2) Tap on an HTTP (not HTTPS) link from the SRP, which opens in a ChromePlate.

3) The ChromePlate will load with a Preview and the snackbar to "Load original" is shown.

4) Tap on three dots menu and "Open in Chrome"

5) Chrome opens a new tab with the same Preview content as before, but no Snackbar is shown.

6) Reloading the Chrome tab will never prompt the user to "Load original".

Observed behavior: 

No "Load original" snackbar is shown when a ChromePlate is opened in a full Chrome Tab with a Preview.

Expected behavior: 

Behavior should be the same regardless of whether the tab was a ChromePlate or not.

Frequency: 
10/10

Additional comments: 

I wonder if this is related to crbug/595975 ?