Since a long time ago, a warning of
"Resource interpreted as Document but transferred with MIME type application/pdf"
has been displayed on the console.
However, no solution to this warning was found.

Is this warning related to this behavior?

These are screenshots from the example URL:

Deleted: pdf1.png 10.6 KB

	pdf1.png 10.6 KB View Download

Deleted: pdf2.png 970 bytes

	pdf2.png 970 bytes View Download

pdf1.png: Screenshot of Chrome 71.0.3578.98 (correct behavior)
pdf2.png: Screenshot of Chrome Canary 73.0.3672.0 (wrong behavior)

I cannot reproduce this from 2 different computers. Can you try launching the browser with the --no-experiments flag, and also try --disable-extensions ?

Wow, I've found that
this bug only occurs in Incognito mode.

Sorry for showing not enough steps to reproduce the problem.

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Still works for me in an Incognito window.

I've tried launching the browser with --no-experiments and --disable-extensions flags,
but neither of them changed the situation.

I found that iframe, object and embed tags have nothing to do with this issue.
http://sinst.html.xdomain.jp/zengaku/jkkn/sample.pdf
Canary can't even display a PDF file directly for me (screenshot below).
Just a gray blank page appears.

What a strange bug.

Deleted: canary_PDF.png 49.4 KB

	canary_PDF.png 49.4 KB View Download

Unable to reproduce the issue on chrome reported version# 73.0.3672.0 using Windows-7 & 10 with steps mentioned below:
1) Launched chrome reported version and navigated to URL: http://sinst.html.xdomain.jp/zengaku/jkkn/chrome_bug11.html
2) Able to see PDF file loaded and displayed successfully
3) Also opened Incognito ode and navigated to URL: http://sinst.html.xdomain.jp/zengaku/jkkn/chrome_bug11.html, PDF file is dispalyed

@Reporter: Please find above mentioned information and attached screencast for your reference. Try to test this issue by creating new person with no apps and extensions in it and let us know if the issue still persists.

Thanks!

Deleted: 922289.mp4 868 KB

	922289.mp4 868 KB View Download

Actually, The PDF document is certainly opened,
and I can select some text on the document (screenshot below).

The PDF has a text like "This is a sample PDF file. The quick...", and I can right click it.
The context menu says "Google で「This is a sample PDF file. The quick brown fox…」を検索(S)".

But anyway, just a gray blank is displayed.

I guess the PDF is correctly loaded, but displayed wrong.

Deleted: canary_PDF2.png 97.1 KB

	canary_PDF2.png 97.1 KB View Download

Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Oh... I feel it's very difficult to figure out why this issue occurs on my side and does not occur on Chromium developers' side

Because of my old OS, Windows 7...? God only knows...

I've just uninstalled & reinstalled Canary, and this issue has gone.
Something was wrong with my PC. Thank you.

This is caused by a field trial flag being enabled on random installations of Canary so you can repro by force-enabling it:
chrome --enable-features=OutOfBlinkCors --incognito http://sinst.html.xdomain.jp/zengaku/jkkn/chrome_bug11.html

Conversely, to disable the bug run chrome with "--disable-features=OutOfBlinkCors"

TE@, this is a duplicate of bug 915546.

Thanks!