[Annotations] The image is no longer displayed in "Edit" mode

[SoftVision-CosminMuntean]

[Affected versions]:

• Nightly 59.0a1
• Screenshots 26.0.0

[Affected Platforms]:

• All Windows
• All Mac OS
• All Linux

[Prerequisites]:

• The "xpinstall.signatures.required" boolean pref is set to "false".
• The "extensions.legacy.enabled" boolean pref is set tot "true".
• Have the Screenshots 26.0.0 dev version installed from here, on a new clean profile.

[Steps to reproduce]:

1. Open Firefox browser with the profile from prerequisites.
2. Navigate to any website and save a selection.
3. Click the "Edit" button and observe the image.

[Expected result]:

• The image is correctly displayed.

[Actual result]:

• The image is no longer displayed.

[Notes]:

• Here is a screen recording with the issue:
  

[SoftVision-CosminMuntean]

This issue is still reproducible using the latest Screenshots 26.0.0 dev version installed from here: https://screenshots.dev.mozaws.net/homepage/install-test-local.html
Tested on Windows 7, Mac Os 10.12 and Arch Linux.

[chenba]

I branched off an earlier master rev where the canvas img crossOrigin attribute was set to "Anonymous"; another patch was merged into master set the attribute to "use-credentials". #3906 will change the attribute back.

[SoftVision-CosminMuntean]

I have retested this issue on latest Screenshots 27.0.0 dev version and is no longer reproducible. Tested on Mac, Linux and Windows. Marking this as verified.