Fix sbox_validation_tests & Make isolate_driver.py include the executable itself

Fix sbox_validation_tests & Make isolate_driver.py include the executable itself

This is a redo of https://codereview.chromium.org/1245873002 c6649f2e014a24a909
with fix for Official build.

Further reduce the boilerplate in .isolate files and is necessary to add debug
symbols, to be done in a follow up.

Slightly accelerate ninja file parsing by blacklisting more extensions.

sbox_validation_tests wasn't run on Windows since
https://codereview.chromium.org/1212003003/ (~2 months ago). Thankfully this CL
uncovered this copy-paste error.

TBR=jam@chromium.org
BUG=98637
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Committed: https://crrev.com/63a4d153f18719fba84e2ce15d03cd2de64e4656
Cr-Commit-Position: refs/heads/master@{#347912}

[M-A Ruel, 2015-09-08 20:40:02]

The relevant delta is
https://codereview.chromium.org/1320793004/diff2/1:20001/tools/isolate_driver.py.
I reproduced the bug caused by patchset #1 on Chrome official build then
confirmed patchset #2 fixed the issue, as there's no try builder testing this
configuration. TBR'ing due to the number of directories touched.

[M-A Ruel, 2015-09-09 12:20:55]

The CQ bit was checked by maruel@chromium.org

[commit-bot: I haz the power, 2015-09-09 12:21:15]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1320793004/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1320793004/20001

[commit-bot: I haz the power, 2015-09-09 12:27:22]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-09-09 12:27:58]

Patchset 2 (id:??) landed as
https://crrev.com/63a4d153f18719fba84e2ce15d03cd2de64e4656
Cr-Commit-Position: refs/heads/master@{#347912}