Add swipe_to_dismiss to Silk benchmark

Add swipe_to_dismiss and stress_hidey_bars to Silk benchmark

This CL adds two tests to the Silk benchmark:

1) swipe_to_dismiss.  In this effect, a message is dismissed from the inbox by
   swiping it to the left.

2) stress_hidey_bars.  In this effect, the messages pane is scrolled down, up,
   and then down again, which provokes the hidey bars to hide, appear, and
   then hide again.

I've also updated inbox_app.html to the latest version. For some reason, the
slide_drawer test is broken with the new verision of the app. I've left an
old_inbox_app.html for that test case, but we should investigate why the test
case doesn't work with the new code.

R=nduca@chromium.org
BUG=332439
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=244087

[nduca, 2014-01-09 22:33:19]

lgtm

[commit-bot: I haz the power, 2014-01-09 22:41:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/132183003/1

[abarth-chromium, 2014-01-09 22:52:24]

I added a test for stressing the hidey bars.

[commit-bot: I haz the power, 2014-01-09 22:59:24]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/132183003/100001

[commit-bot: I haz the power, 2014-01-09 23:19:23]

Failed to trigger a try job on win_x64_rel
HTTP Error 400: Bad Request

[commit-bot: I haz the power, 2014-01-09 23:23:06]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/132183003/90002

[commit-bot: I haz the power, 2014-01-10 01:23:15]

Retried try job too often on linux_aura for step(s) interactive_ui_tests
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=linux_aura...

[commit-bot: I haz the power, 2014-01-10 01:47:32]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/abarth@chromium.org/132183003/90002

[commit-bot: I haz the power, 2014-01-10 04:55:16]

Change committed as 244087