Reset the list of sequence switch key codes when switching key maps.

Reset the list of sequence switch key codes when switching key maps.

Issue:
- press Search+Shift+Q+Q (to switch to Next).
- press Search+Q (to switch to Classic)
- press Search+Shift+Q+Q (to again switch to Next)
- press another key like right arrow.

result:
toogleChormeVoxVersion gets issued again and you get flipped back to classic.
cvox.ChromeVox.sequenceSwitchCodes contains a lot of stale information; most importantly, it now considers Cvox+Q a sequence when it isn't one in Next.

TEST=Verify the above is fixed.

Committed: https://crrev.com/baef6824e2ea719979aa9db98c87b041f2875a2f
Cr-Commit-Position: refs/heads/master@{#360644}

[David Tseng, 2015-11-19 18:27:26]

Description was changed from

==========
Reset the list of sequence switch key codes when switching key maps.
==========

to

==========
Reset the list of sequence switch key codes when switching key maps.

Issue:
- press Search+Shift+Q+Q (to switch to Next).
- press Search+Q (to switch to Classic)
- press Search+Shift+Q+Q (to again switch to Next)
- press another key like right arrow.

result:
toogleChormeVoxVersion gets issued again and you get flipped back to classic.
cvox.ChromeVox.sequenceSwitchCodes contains a lot of stale information; most
importantly, it now considers Cvox+Q a sequence when it isn't one in Next.


TEST=Verify the above is fixed.
==========

[David Tseng, 2015-11-19 18:27:26]

dtseng@chromium.org changed reviewers:
+ dmazzoni@chromium.org

[dmazzoni, 2015-11-19 18:41:19]

The CQ bit was checked by dmazzoni@chromium.org

[dmazzoni, 2015-11-19 18:41:19]

lgtm

[commit-bot: I haz the power, 2015-11-19 18:41:49]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1459263002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1459263002/1

[commit-bot: I haz the power, 2015-11-19 19:46:29]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-19 19:47:10]

Patchset 1 (id:??) landed as
https://crrev.com/baef6824e2ea719979aa9db98c87b041f2875a2f
Cr-Commit-Position: refs/heads/master@{#360644}