hterm: Support to detect alt-backspace when it's remapped to DEL.


TEST=Manually tested the following cases before and after to see the
same behavior w/ the pref disabled:
DEL: 0x1b 5b 33 7e == '\x1b[3~'
Backspace: 0x7f
Esc: 0x1b
Alt-Del: 0x1b 5b 33 3b 33 7e == '\x1b[3;3~'

And w/ the pref enabled, saw that Alt-backspace did:
Alt-Backspace: 0x1b 7f (this is the only chage from this CL)

Change-Id: Ie480d7087495704c7e3417d08c4e99702d5f85a0
Reviewed-by: Robert Ginda <>
Commit-Queue: Andrew de los Reyes <>
Tested-by: Andrew de los Reyes <>
5 files changed
tree: 0bacac0336b88e6b079ab2316f4d35e59c22239b
  1. crosh_builtin/
  2. hterm/
  3. libdot/
  4. nassh/