title: Send escape key rather than alt in chrome ssh
body: <p>I am using the chrome ssh extension to ssh into an ubuntu machine.
  I have got myself a new 60% keyboard to use with it and as a result, no longer have the backtick as a stand-alone key. I had been using the backtick as the prefix key for tmux.
  I have now mapped the escape key as the prefix in tmux however hitting escape+c which should open a new window on tmux now seems to send the equivalent of alt+c.</p>
  <p>If I hit the keys a bit slower then the window is created however going slower is not a good enough solution as it breaks my concentration.</p>
  <p>The alt key itself seems to send special characters.</p>
  <p><strong>update</strong></p>
  <p>So I have been doing more investigation into the way the key events are handled in the app. I have a feeling it might have something to do with the  following <a href="https://chromium.googlesource.com/apps/libapps/+/master/hterm/js/hterm_keyboard.js" rel="nofollow noreferrer">function</a>:
  <a href="https://i.stack.imgur.com/3xId1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/3xId1.png" alt="enter image description here" /></a></p>
  <p>I think my best guess now is that by hitting the ESC key too close to another key, both are being picked up by the keystroke event handler at once. From reading through the key handling code; it seems that the ALT+1 is sent as if it was an ESC followed by a 1.</p>