Comment 671 for bug 263435

Created attachment 827318
PoC patch for both winless and windowed plugins. (Windows)

This proposal is a sensible workaround (as a "complete" solution would
require the collaboration of every single plugin developer, which
doesn't seem feasible) for Windows. Is my understanding that OSX is
not affected, and a solution already exists for GNU/Linux, please
correct me if I'm wrong.

I've implemented two different strategies, one for plugins running in
its own window, and the other for the winless ones. The first one
installs a keyboard hook, which looks for well known keystrokes, and
passes the focus to the main window when one is found. The second
passes all key events to both the plugin and the DOM, except for the
ones which generates movement events (arrow keys, space,
pageup/pagedown...).

This patch is intended as a Proof-of-Concept, it needs betters
comments, an approved list of keystrokes to watch, and (probably) the
ability to be enabled/disabled via "about:config". But I wanted to
obtain early feedback from the devs prior to investing more work on
it.