Printing causes process to crash

[abentele]

Issue Details

• Electron 5.0.5 - 6.0.1 (see list below)
• macOS 10.14.6

Similar to issues #15188/#15143 (which are already closed/merged).

Expected Behavior

Basic printing (Browser API window.print()) works.

Actual Behavior

Application process crashes when printing.

To Reproduce

Electron Fiddle repro here (same as for issue #15188):
https://gist.github.com/bf55ecc157b5e4d4a69a0a07e0ac0610

To reproduce:

• open the Fiddle with Electron Fiddle (version 0.9.0), select the Electron version and start the app with "Run"
• click on the main page; the print dialog is opened
• in the print dialog, click "Print"

Reproducible (versions), related to the Fiddle and to my private real-world application:

• Electron 4.2.6 => not reproducible with Fiddle / not reproducible with my real-world app
• Electron 4.2.9 => not reproducible with Fiddle / not reproducible with my real-world app
• Electron 5.0.0 => not reproducible with Fiddle / reproducible with my real-world app
• Electron 5.0.4 => not reproducible with Fiddle / reproducible with my real-world app
• Electron 5.0.5 => reproducible with Fiddle
• Electron 5.0.6 => reproducible with Fiddle
• Electron 5.0.7 => reproducible with Fiddle
• Electron 5.0.8 => reproducible with Fiddle
• Electron 5.0.9 => reproducible with Fiddle
• Electron 6.0.0 => reproducible with Fiddle
• Electron 6.0.1 => reproducible with Fiddle / reproducible with my real-world app
• Electron 7.0.0-beta.1 => not reproducible with Fiddle

macOS crash report (crash of Electron 6.0.1):
crash-report.txt

[codebytere]

This will be fixed in the next release of 6/5, once this PR is backported.