views: Support transparent overlay BrowserViews #4035
Description
Is your feature request related to a problem? Please describe.
We currently have the capability to add a CefBrowserView overlay via CefWindow::AddOverlayView. However, the GetColor implementation requires windowed browsers to be fully opaque. We should allow transparency in the overlay case.
This would most likely be configured by setting CefBrowserSettings.background_color with a transparent alpha component prior to BrowserView creation, but we could also potentially use CefBrowserViewImpl::SetBackgroundColor to change the value during runtime.