Agreed - all of the top row of function keys need spoken labels. Also, for the mute key, we should speak mute first and consider not allowing mute to actually work in this mode. We've received reports of users muting and then not knowing what happened. 

Just bumping this back up after getting more feedback on this at ATIA. In the keyboard Learn Mode, we really need to fix the issue with the function keys still working, The volume keys are just about the only keys that should still work (volume up and volume down). Everything else should honestly be disabled to not work and only have ChromeVox say what the key is.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/71057143def7c919dae207f13c207ecc47e6ed09

commit 71057143def7c919dae207f13c207ecc47e6ed09
Author: David Tseng <dtseng@chromium.org>
Date: Mon Feb 19 05:39:32 2018

Allow capture of f1-f12

History:
At some point in the past, SpokenFeedbackEventRewriter did not have the notion of |capture| (a boolean set by a calling extension). As a result, we had to hard code values into the rewriter so that they get rewritten by things like KeyboardDrivenEventRewriter. For example, F1->back.

This leads to us not being able to capture and prevent default on F1-F12 which map to hardware keys.

Bug:  687748 
Test: Search+o, k; verify f1-f12 announce and don't trigger.
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: I3ca70a8fc1159f9b5f60332ef5a77ecfe95482b7
Reviewed-on: https://chromium-review.googlesource.com/905283
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537582}
[modify] https://crrev.com/71057143def7c919dae207f13c207ecc47e6ed09/chrome/browser/chromeos/accessibility/spoken_feedback_event_rewriter.cc
[modify] https://crrev.com/71057143def7c919dae207f13c207ecc47e6ed09/chrome/browser/resources/chromeos/chromevox/chromevox/background/kbexplorer.js