not reproduced on Chrome:53.0.2785.103/ChromeOS:8530.81.0/ARC:3251841 

Having the same issue on 54.0.2840.13 dev (64-bit).

Opening PDFs saved in Drive display like this:
https://drive.google.com/file/d/0By8giC4xerz-WjA0TGpmMTRrZUE/view?usp=sharing

PDFs from weblinks open fine.

I have exactly the same issue since the latest update. I can open PDFs in my Downloads folder, but when I try to open any PDF from my Google Drive I see the same thing as shown in Comment 2.

 Issue 649190  has been merged into this issue.

We are seeing user complaints on CBC and have verified that we can consistently reproduce this problem.

#CBC-RS/TC-watchlist

Yeah I'm having this issue too, it happens for every Drive stored pdf that I have.

I am building a new Beta RC tomorrow, please comment if this bug is feasible to be fixed by then 

I just sent a CL for this issue, so the next beta will not have the fix.
https://codereview.chromium.org/2370223002/

 Issue 650646  has been merged into this issue.

I have shared a file (Simple Instruction.pdf).
You may see a video which reproduce the issue here: https://youtu.be/OFoUZrlPdis

fukino, can you merge the fix CL to M-54 once landed in ToT?

Yes, I'll merge the fix to M54.
The fix https://codereview.chromium.org/2370223002/ has already landed on master, but this issue was not updated for some reason.

The fix was merged to M54.
https://codereview.chromium.org/2378753002
(This issue has yet been updated by the commit, though)

Marking this as Fixed and manually adding Merged labels as bugdroid doesn't update it for some reason.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/bbf2420306f6d0a3c85d10a4115ab254b3912162

commit bbf2420306f6d0a3c85d10a4115ab254b3912162
Author: fukino <fukino@chromium.org>
Date: Wed Sep 28 04:34:18 2016

Add externalfile: to PDF extension's object-src.

externalfile:// scheme is used in Chrome OS to open external files (e.g. files in Google Drive) in a browser tab.
After https://codereview.chromium.org/2209113002/, we need to specify it in PDF extension's CSP permissions.

BUG= 645285 
TEST=manually tested the repro steps in the bug description.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2370223002
Cr-Commit-Position: refs/heads/master@{#421447}

[modify] https://crrev.com/bbf2420306f6d0a3c85d10a4115ab254b3912162/chrome/browser/resources/pdf/manifest.json

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b4f6f52b011f0f6a7e30b805934a15e04a644ab8

commit b4f6f52b011f0f6a7e30b805934a15e04a644ab8
Author: Naoki Fukino <fukino@chromium.org>
Date: Wed Sep 28 15:31:17 2016

Add externalfile: to PDF extension's object-src.

externalfile:// scheme is used in Chrome OS to open external files (e.g. files in Google Drive) in a browser tab.
After https://codereview.chromium.org/2209113002/, we need to specify it in PDF extension's CSP permissions.

BUG= 645285 
TBR=raymes@chromium.org
TEST=manually tested the repro steps in the bug description.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2370223002
Cr-Commit-Position: refs/heads/master@{#421447}
(cherry picked from commit bbf2420306f6d0a3c85d10a4115ab254b3912162)

Review URL: https://codereview.chromium.org/2378753002 .

Cr-Commit-Position: refs/branch-heads/2840@{#561}
Cr-Branched-From: 1ae106dbab4bddd85132d5b75c670794311f4c57-refs/heads/master@{#414607}

[modify] https://crrev.com/b4f6f52b011f0f6a7e30b805934a15e04a644ab8/chrome/browser/resources/pdf/manifest.json

 Issue 651958  has been merged into this issue.

I don't know how the bug system works, so this may be expected: the bug still appears in today's dev channel update.

55.0.2869.0 dev (64-bit)
8838.0.0 (Official Build) dev-channel quawks

Verified on Chrome OS  54.0.2840.49/8743.54.0 beta cyan
 Samus 55.0.2878.0/8858.0.0 dev-channel

 Issue 652821  has been merged into this issue.

Looks like this is still an issue. 

Issue exists in  55.0.2842.0 but its fixed in version 55.0.2878.0+

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b4f6f52b011f0f6a7e30b805934a15e04a644ab8

commit b4f6f52b011f0f6a7e30b805934a15e04a644ab8
Author: Naoki Fukino <fukino@chromium.org>
Date: Wed Sep 28 15:31:17 2016

Add externalfile: to PDF extension's object-src.

externalfile:// scheme is used in Chrome OS to open external files (e.g. files in Google Drive) in a browser tab.
After https://codereview.chromium.org/2209113002/, we need to specify it in PDF extension's CSP permissions.

BUG= 645285 
TBR=raymes@chromium.org
TEST=manually tested the repro steps in the bug description.
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2370223002
Cr-Commit-Position: refs/heads/master@{#421447}
(cherry picked from commit bbf2420306f6d0a3c85d10a4115ab254b3912162)

Review URL: https://codereview.chromium.org/2378753002 .

Cr-Commit-Position: refs/branch-heads/2840@{#561}
Cr-Branched-From: 1ae106dbab4bddd85132d5b75c670794311f4c57-refs/heads/master@{#414607}

[modify] https://crrev.com/b4f6f52b011f0f6a7e30b805934a15e04a644ab8/chrome/browser/resources/pdf/manifest.json

Got the same bug on samus
CHROME VERSION
69.0.3486.0 dev
Can't open any pdf in files app except downloads.