Windows builds are unresponsive after starting

[jdm]

I suspect this was introduced in #23457, since the window changes sizes frequently and contains large black areas.

[jdm]

Confirmed. This regressed in #23457, based on running local builds made before and after that change.

[jdm]

I made a build with 0.20 and it worked, so that at least narrows the range.

[jdm]

Filed rust-windowing/glutin#1163.

[jdm]

@paulrouget Is there any chance this is triggered by the implementation in https://github.com/servo/servo/blob/master/ports/glutin/context.rs rather than the changes in rust-windowing/glutin@90f0ef4?

[jdm]

rust-windowing/glutin#1163 (comment) points out that our code that calls window.set_inner_size in response to the Resize event is wrong. When I fix that the flickering resizing window goes away, but Servo remains unresponsive. This is caused by the Resize window event that Servo enqueues causes a synchronous repaint to occur, except no composite is scheduled so the compositor is hung indefinitely and no window events can be processed that might trigger one.