Don't toggle menu unless ALT was the last key pressed

[bsclifton]

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).

Don't toggle menu unless ALT was the last key pressed
This prevents ALT codes from toggling menu

Fixes #4295

Auditors: @jonathansampson, @BrendanEich

Test Plan:

1. Launch Brave on Windows and go to http://jsbin.com
2. Click inside a text area and type a few letters
3. Push ALT (left) and release to confirm menu shows and do same to hide it
4. Push and hold ALT (left), key in 0133, then let go of ALT
5. The ellipsis should be typed out and the menu should NOT have been toggled

[jonathansampson]

LGTM

[bbondy]

💯

[luixxiul]

I cannot confirm this.

3 Push ALT (left) and release to confirm menu shows and do same to hide it

Pushing left alt key does not oepn the menu. Is this because of difference between keyboard layouts?

[srirambv]

Push and hold ALT (left), key in 0133, then let go of ALT

This doesn't type ellipse for me but the menu doesn't toggle. However pressing Alt+PrintScreen still shows the menu for me after the keys are released

[luixxiul]

I confirmed it right now. @bsclifton suggested me it has been due to the focus issue.