The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/dbbea180ec5643783dc6a41bc643bd0c36189cba

commit dbbea180ec5643783dc6a41bc643bd0c36189cba
Author: Katie Dektar <katydek@google.com>
Date: Thu Jan 04 23:08:53 2018

Adds speech pitch control in select-to-speak settings.

Gives the users 6 options for pitch, from 0.55 through 1.3.

Bug:  796745 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Ic13c4098ff0c3629a1faa4c8a063a287492d8696
Reviewed-on: https://chromium-review.googlesource.com/838247
Commit-Queue: Katie Dektar <katie@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#527135}
[modify] https://crrev.com/dbbea180ec5643783dc6a41bc643bd0c36189cba/chrome/browser/resources/chromeos/select_to_speak/options.html
[modify] https://crrev.com/dbbea180ec5643783dc6a41bc643bd0c36189cba/chrome/browser/resources/chromeos/select_to_speak/select_to_speak.js
[modify] https://crrev.com/dbbea180ec5643783dc6a41bc643bd0c36189cba/chrome/browser/resources/chromeos/select_to_speak/select_to_speak_options.js
[modify] https://crrev.com/dbbea180ec5643783dc6a41bc643bd0c36189cba/chrome/browser/resources/chromeos/select_to_speak/strings/select_to_speak_strings.grd

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/f8fb07063ccc7712dc327ef87c5261b6dd80be1d

commit f8fb07063ccc7712dc327ef87c5261b6dd80be1d
Author: Katie Dektar <katydek@google.com>
Date: Tue Jan 09 01:27:19 2018

Adds metrics for speech pitch in Select-to-Speak.

Bug:  796745 
Cq-Include-Trybots: master.tryserver.chromium.linux:closure_compilation
Change-Id: Iba2b3a474ccf20bbbed650a66c5aa0054e01217c
Reviewed-on: https://chromium-review.googlesource.com/853139
Commit-Queue: Katie Dektar <katie@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#527851}
[modify] https://crrev.com/f8fb07063ccc7712dc327ef87c5261b6dd80be1d/chrome/browser/resources/chromeos/select_to_speak/select_to_speak.js
[modify] https://crrev.com/f8fb07063ccc7712dc327ef87c5261b6dd80be1d/tools/metrics/histograms/enums.xml
[modify] https://crrev.com/f8fb07063ccc7712dc327ef87c5261b6dd80be1d/tools/metrics/histograms/histograms.xml

Google Chrome 67.0.3369.0 (Official Build) canary (64-bit)
Firmware Version Google_Samus.6300.276.0
Flag enabled: #enable-experimental-accessibility-features

Tested the pitch setting in STS settings. All of the items in the combobox work as expected, the pitch lowers or raises as expected. Swapping them rapidly also works as long as I restart the speech between each selection. 

Moving from just having STS label to also having the UI>Accessibility>SelectToSpeak component to make searching easier in the future.