alloy: Print preview fails to load PDF renderer (M124)

[Marshall Greenblatt]

To Reproduce
Steps to reproduce the behavior:

1. Run cefclient --enable-print-preview
2. Select Tests > Print from the top menu.

Expected behavior
The preview frame should load successfully. Instead, it shows "Loading preview..." until the dialog is canceled.

Versions (please complete the following information):

• OS: All platforms
• CEF Version: M124

Additional context
Does not reproduce with Chrome runtime (Chrome or Alloy style). Does not reproduce with M123.

[Marshall Greenblatt]

Alloy bootstrap is deprecated (see #3685). Issues that only reproduce with Alloy bootstrap are being closed as WontFix.