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• I have read the Contributing Guidelines for this project.
• I agree to follow the Code of Conduct that this project adheres to.
• I have searched the issue tracker for an issue that matches the one I want to file, without success.

Issue Details

When setting nativeTheme.themeSource to 'dark' (or 'system' and setting the system theme to 'dark'), the title bar on Windows remains light. On macOS, the title bar accurately reflects the setting.

• Electron Version:
  • npm ./node_modules/.bin/electron --version: 6.9.0
  • package.json: "electron": "^8.2.5",
  • yarn.lock: 8.2.5
• Operating System:
  • Windows 10 (1903)

Expected Behavior

(This works as expected on macOS)

Actual Behavior

To Reproduce

nativeTheme.themeSource = 'dark'

Screenshots

Command Prompt:

File Explorer:

Title Bar in Electron with nativeTheme.themeSource = 'dark'