WebMidi: use testRunner.setPermission in addition of .setMIDISysexPermission.

WebMidi: use testRunner.setPermission in addition of .setMIDISysexPermission.

This is a transition CL to allow Chromium to stop supporting the
setMIDISysexPermission call.

This CL is part of a suite of four patches:
Part 1: <this>
Part 2: https://codereview.chromium.org/1100673004
Part 3: https://codereview.chromium.org/1097933006
Part 4: https://codereview.chromium.org/1095233005

BUG=475141
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=194247

[mlamouri (slow - plz ping), 2015-04-22 14:41:34]

mlamouri@chromium.org changed reviewers:
+ mkwst@chromium.org

[mlamouri (slow - plz ping), 2015-04-22 14:41:35]

Mike, PTAL.

[mlamouri (slow - plz ping), 2015-04-22 14:50:50]

The CQ bit was checked by mlamouri@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2015-04-22 14:51:14]

Dry run: CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1100843003/1

[Mike West, 2015-04-22 15:14:11]

LGTM.

[commit-bot: I haz the power, 2015-04-22 22:17:09]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-04-22 22:17:11]

Dry run: Try jobs failed on following builders:
  win_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/win_blink_rel/builds/60328)

[mlamouri (slow - plz ping), 2015-04-22 22:20:52]

The CQ bit was checked by mlamouri@chromium.org

[commit-bot: I haz the power, 2015-04-22 22:21:58]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1100843003/1

[commit-bot: I haz the power, 2015-04-22 23:20:36]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=194247