ChromeOS version: 66.0.3359.181
ChromeOS device model: any ChromeOS (tested: Panther and Swanky)
We also confirmed the same behavior from other OS such as MAC and WIN.
Case#: 15869638

Description: Can not download the attached PDF file from Gmail if “Download PDF files instead of automatically opening them in Chrome” setting is enabled.

Steps to reproduce: 
1. Go to chrome://settings/content/pdfDocuments
(settings>Advanced>Privacy and security>Content settings>PDF documents)
2. Enable “Download PDF files instead of automatically opening them in Chrome” setting.
3. Access to Gmail and open an e-mail that PDF file is attached.
4. Click download icon “↓ “ , but the download process never starts.



Please refer the attached vide file for repro steps.
https://drive.google.com/open?id=17oV0NHzFSmPkFlAQoci4IaHPAKLBwPkW

Investigation notes.
-I could not reproduce the same behavior on M65(65.0.3325.184) device.
https://drive.google.com/open?id=1n-lXZs4Q2GO5ET7A_PmAZ57srCKl70Ik

-I could reproduce the same behavior on Mac (V10.13.4) with Chrome Browser 66.0.3359.181 stable.
-The customer is able to reproduce the same behavior on Windows 10 device as well.
-I tested a few different types of attachments, but I could not reproduce the same behavior.
-verified the same behavior on Beta and Canary.

Current Behavior / Reproduction: 
the customer is not able to download the attached PDF file from Gmail if “Download PDF files instead of automatically opening them in Chrome” setting is enabled.

Expected Behavior: 
able to download the attached PDF file from Gmail even “Download PDF files instead of automatically opening them in Chrome” setting is enabled.


Drive link to logs: 
Time stamp: May 22 at 15:40
https://drive.google.com/open?id=1rNq20YEaO22hU0ic_mn2DEhYBizraiLI

could be relating with other crbug cases.
crbug.com/806711