Thanks for filing the issue!

Unable to reproduce the issue on reported chrome version 72.0.3608.0 using Windows 7 and Windows 10 with the below mentioned steps.
1. Launched Chrome
2. Opened index.html file in a new file
3. Clicked on Choose file
4. Tried dragging the dialogue over the screen.
We didn't observe any trails/traces in the process. Attaching the screencast of the same for reference. 

@Reporter: Could you please check the same in a new profile without any apps and extensions and let us know if the issue still persists. Any further inputs from your end may be helpful.

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Here is our virtual machine: https://drive.google.com/open?id=1EIJG1jkT4Zq-1zIqbh0LpkhFRTNUg9lA
VirtualBox is needed in order to run it. Disable internet connection before launching it to prevent Chrome updates. The password for the archive is the ID of this issue. The virtual machine will be removed one week from now, so we hope someone can confirm the issue in that period. Thanks.

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

As we do not have set up with virtual box to run/test this, however requesting someone from inhouse team for help in triaging this further. Hence adding label "TE-NeedsTriageFromHYD".

Thanks!

Tested this on VMWare on Windows-7 with the attached gpu on the latest canary 72.0.3612.0 and didn't observe any file dialog rendering issue as updated in C#0. Somehow, suspecting this to be gpu issue than to be virtual box related.

@reporter: Could you please check the issue by disabling the 'Use hardware acceleration when available' under chrome://settings > System and let us know if the issue is resolved. Please attach chrome://gpu details. Also cross check this in new user profile with default settings.

Thank you!

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The purspose of our virtual machine is to provide a way for reproducing the issue in exact same environment. Can you please run our virtual machine in VirtualBox. The GPU from C#6 doesn't match our machine's GPU, so we assume you tested on different machine. We are providing here our GPU and another screencast. Also tested in a fresh profile with default settings and no apps, extensions and plugins.

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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

@reporter: Could you please re-share the C#3 virtual machine with ajha@chromium.org, looks like access has expired. I am trying to do the virtual box set up to test this.

It's now available again.

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

Looks like this isn't specific to virtual machine set up. Issue is reproducible on the latest canary 72.0.3617.0 on Windows-7 and doesn't repro on equivalent signed/unsigned build.

This seems to be related to flag: out-of-blink-cors. Disabling the flag seems to resolve the issue but issue is seen with default status of this flag. Attaching the screen-cast of the testing.

toyoshim@@: Could you please take a look at this and help in further investigation. 

Note: Not adding any blocker as the issue is specific to canary channel.  

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I do not think this issue can be caused by out-of-blink-cors.
The test case does not run any relevant code path.

Also, I could not reproduce the problem on the latest canary 72.0.3263.0 (32-bit) on Windows 7, with out-of-blink-cors enabled.

Can you make sure if the issue can be solved by this flag change consistently? I'm afraid other Default settings are randomly changed, and results in this by chance.

restore some labels for attentions.

Tested this issue as per C#13, i am consistently able to repro this issue with out-of-blink-cors flag enabled or in default status using latest canary #73.0.3630.0 on windows 7 and doesn't repro on equivalent signed/unsigned build.

Thanks!

'default' results in enabled for 50% trials, and disabled for another 50% trials.
So if this consistently happens with default, that means this is not related to out-of-blink-cors.

Able to reproduce the issue on win 7 canary build-73.0.3631.0.Unable to reproduce the issue on Windows 7 using latest canary equivalent signed build#73.0.3631.0 & unsigned builds as per C#0.As testing team unable to reproduce the issue on signed & unsigned builds of canary, removing needs-bisect label for now.Please add if it consistently reproduce the issue on equivalent builds.
Thanks..!