I was unable to reproduce the issue on Windows-10, chrome version: 59.0.3071.115. Copy-paste worked fine from Firefox or Notepad to Chrome and vice versa.

@reporter: Could you please confirm the chrome version and environment where the issue is seen?

Hello, I was able to repro this on 59.03071.115 64 bit on Win10. 

It seems to happen while I have a dialog open, in my case the "Profile error occurred" dialog that pops up when using a profile from a newer version of Chrome. 

Easy-ish repro steps on M59: 
* Run trunk Chrome / canary chrome pointed at the --user-data-dir of stable chrome to make the profile version incompatible with stable.
* Run Chrome stable, get the "Profile error occurred" dialog, do not dismiss it.
* Interact with the main Chrome browser window and try to copy text, see text not being copied.
* Close the profile error dialog.
* Try and copy text from the browser window, it works again.

The dialog is neither system nor browser modal so I can still interact with the other browser windows, but copying text from web content seems to stop working. 

Because this bug has the word "dialog" in it, I'm CCing our dialog guru. Also +Abdul in case he knows who else might now about this. If the cause isn't obvious, I'll try debugging some more. 

I'll bump this to P2 as well since Chrome does pop up dialogs every once in a while and this does break something quite user visible when it happens.

Is this Windows/Views-only, or does the Mac behave in the same way?

+Views person

On Mac the dialog is modal to the browser window so it doesn't allow interaction with the browser window to copy.

Also on Mac, the dialog pops up three times in a row on my local machine. At a guess it pops up once for each profile even though there's only one browser window open, maybe profile initialization is done differently.

To test on Mac (with stable and canary installed):

/Applications/Google\ Chrome.app/Contents/MacOS/Google\ Chrome --user-data-dir=$HOME/Library/Application\ Support/Google/Chrome\ Canary/

Sorry! This bug fell through the cracks because sheriff bot did not remove the NeedsFeedback label -- https://crbug.com/monorail/4357

cc-ing huangdarwin@ for prioritization. Switched back to Uncofirmed because this bug is over a year old, and we should first check it's still happening.

I'm unable to repro on Mac and Linux Chrome 69/70, using directions from #2 and #4, as I'm unable to trigger the "Profile error occurred" error/pop-up.

Also tried repro'ing with a modal dialog from GMail's "attach file". On Mac and Linux, the dialog is modal as #4 mentioned.

Repro steps I'm trying:
1. Open Gmail -> Compose
2. Copy/Paste works (as expected)
3. Open "Attach File" dialog
4. Copy/Paste within dialog works, but from browser doesn't (makes sense on Linux/OSX because it's modal, but I"m curious how Windows reacts)

Tried on Windows with pwnall and wasn't able to repro the "Profile Error occurred" pop-up as per #2. Also wasn't able to experience this via steps in #6, as the compose dialog is also modal on Windows. 

Going to mark as WontFix due to lack of repro. Please let me know if there are repro steps that still work now, and I'll reactivate it.