Without continuous MouseMove events, Servo never updates hover state:
no cursor changes over links, no :hover CSS effects, no mouseenter
JavaScript events. The web page appears completely non-interactive.
Track mouse position from GPUI on_mouse_move through the full IPC
pipeline to Servo. Hover position is included with each ensure
request so Servo updates hover state at frame rate (~60fps).
Enter, Backspace, Tab, Escape, Delete, arrow keys, Home, End,
PageUp, PageDown now forward to Servo. Previously only printable
characters reached the web engine, making forms unusable.
ZacharyZhang-NY