Fix testing/scripts/mojo_apptests.py command for Windows.

Fix testing/scripts/mojo_apptests.py command for Windows.

Use sys.executable to run the python script on Windows.

BUG=592043
TEST=Step passes on Windows.
TBR=dpranke@chromium.org

Committed: https://crrev.com/bb63eb68c886cd3dd5f0e30d73e1e7d52b942958
Cr-Commit-Position: refs/heads/master@{#379354}

[msw, 2016-03-04 19:13:17]

Hey Dirk, PTAL as you have time; landing.

[msw, 2016-03-04 19:13:26]

The CQ bit was checked by msw@chromium.org

[commit-bot: I haz the power, 2016-03-04 19:13:42]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1768633002/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1768633002/1

[Dirk Pranke, 2016-03-04 20:38:54]

lgtm

[commit-bot: I haz the power, 2016-03-04 20:57:36]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-03-04 20:59:20]

Description was changed from

==========
Fix testing/scripts/mojo_apptests.py command for Windows.

Use sys.executable to run the python script on Windows.

BUG=592043
TEST=Step passes on Windows.
TBR=dpranke@chromium.org
==========

to

==========
Fix testing/scripts/mojo_apptests.py command for Windows.

Use sys.executable to run the python script on Windows.

BUG=592043
TEST=Step passes on Windows.
TBR=dpranke@chromium.org

Committed: https://crrev.com/bb63eb68c886cd3dd5f0e30d73e1e7d52b942958
Cr-Commit-Position: refs/heads/master@{#379354}
==========

[commit-bot: I haz the power, 2016-03-04 20:59:22]

Patchset 1 (id:??) landed as
https://crrev.com/bb63eb68c886cd3dd5f0e30d73e1e7d52b942958
Cr-Commit-Position: refs/heads/master@{#379354}