[Feature Request]: BrowserView → Support Window Controls Overlay

[arman-canva]

Preflight Checklist

• 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 a feature request that matches the one I want to file, without success.

Problem Description

Currently, there is no obvious way to use the Window Controls Overlay (WCO) API from BrowserViews or webContents therein.

This is particularly inconvenient when using BrowserViews within BrowserWindows that have had the WCO API enabled using steps outlined here.

When this is the case, window controls are prone to be rendered over BrowserView content.

Currently, the WCO API isn't exposed to BrowserViews that have been added by way of BrowserWindow.addBrowserView/equivalent to BrowserWindows that have it enabled.

As a result, there is no obvious/OOTB way of signalling to BrowserViews/their contents when window controls are visible or how large they are.

Proposed Solution

Introduce means for enabling Window Controls API for BrowserViews/their webContents — ideally, with options for controlling whether window controls themselves are actually visible.

Optional: Automatically do this when BrowserViews are associated with BrowserWindows using addBrowserView or similar.

Alternatives Considered

Thinking out loud:

• Expose key Window Controls API values from BrowserWindows via some additional methods; e.g. BrowserWindow:: getTitlebarAreaRect() and/or BrowserWindow::getWindowControlsAreaRect()

Additional Information

A GitHub Gist that demonstrates the availability of the WCO API in BrowserWindow, but not associated BrowserViews: https://gist.github.com/2d5e4dfa9f9a02644c9cf1f8fd04848b

[ckerr]

CC @jkleinsc as fugu-related