Thanks for filing the issue!

Tried checking the issue on reported chrome version 69.0.3497.100 using Windows 10 with the below mentioned steps.
1. Launched Chrome 
2. Downloaded the ChromeApp.zip -> extracted
3. Navigated to Chrome://extensions, loaded the unpacked extension by switching developer mode ON.
4. Observed Chrome Apps, webview test 1.0 added successfully.

@Reporter: As we are not very clear/sure about "the PDF hosted inside the guest view of the app", could you please elaborate on the same. Any further inputs from your end may be helpful for further triaging the issue.

The attached app includes a pdf that is loaded inside the webview in the provided app.  Do the steps in the report on that pdf.

Oh and you obviously need to start the app itself from chrome://apps as with any app. 

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

Able to reproduce the issue on reported chrome version 69.0.3497.100 and on the latest canary 71.0.3559.0 using Windows 10, Ubuntu 14.04 and Mac 10.13.1

Bisect Information:
--------------------
Good Build: 63.0.3223.0
Bad Build:  63.0.3225.0

You are probably looking for a change made after 504421 (known good), but no later than 504422 (first known bad).
CHANGELOG URL:  https://chromium.googlesource.com/chromium/src/+log/1b62135c07abbd0fb531b03fddb3c2114cb06698..3131414035a033d1fb624913474dbdac04158198
Suspecting: https://chromium.googlesource.com/chromium/src/+/3131414035a033d1fb624913474dbdac04158198
Review URL: https://chromium-review.googlesource.com/680158

@Lucas Furukawa Gadani: Please help in assigning it to the right owner, if this is not related to your change.

Thanks!

This causes breakage for us at Vivaldi so some priority fix would be highly appreciated. 

This is not <webview>/GuestView-specific, any PDF loaded inside an OOPIF doesn't work with ctrl+c.

Ehsan, can you take a look?

I can see Ctrl + C does not work but right click and copy works. I will take a look.

This is most probably a focus problem. I replaced the test PDF file with a PDF file with <input> fields and noticed that keyboard does not work :-).

Some notes:

  * Comment #8: Generally speaking MHV in OOPIF works fine. Basically if you add any <iframe> to a cross origin PDF you are indeed embedding a MimeHandlerView inside OOPIF because the <iframe> will have a PluginDocument in the origin of the PDF file. This works correctly btw (as far as the keyboard focus is involved).

  * Inside an OOPIF, if you manually add <embed type="application/pdf"> you would also have to do something like embed.focus() for keyword to work. Unfortunately mouse clicks do not give keyboard focus in this case.

  * In the given APP even manually focusing the <embed> does not quite work. This seems like a more generic bug.

All in all I see keyboard focus mishap in all of this. I am not quite familiar with focus logic with inner/outer WebContentses so I will pass it on to James for triage.

James could you please take a look? Feel free to assign back to me if you can't find a better owner.

Also cc-ing avallee@ who had a lot of focus contributions to guests. 

Also cc-ing alexmos@ for OOPIF focus.

Any progress here?