Update StringPrintfTest.Invalid for VS 2015

Update StringPrintfTest.Invalid for VS 2015

VS 2015's vswprintf handles invalid unicode differently from VS 2013. The usage
of vswprintf through SStringPrintf and friends has been audited and this change
should not be a problem, so the test has been changed to let it pass instead of
blocking the compiler upgrade.

R=cpu@chromium.org
BUG=533002, 440500
Committed: https://crrev.com/4f5d484cfe4e2bb268dd479b6fbc23963aac564b
Cr-Commit-Position: refs/heads/master@{#357964}

[brucedawson, 2015-11-03 21:58:48]

This test fails on VS 2015, but there is no indication that this matters. The
test checks how vswprintf behaves when passed invalid wchar_t* strings, but we
should not be passing invalid strings. This test needs to be removed or updated
before we can move Chrome to VC++ 2015.

The Chromium code was audited and it was found that most uses of the whcar_t
SStringPrintf, SStringPrintf, StringAppendF, and StringAppendV functions were
operating only on hard-coded strings and integers. After discussions with evanm
the one call site that seemed to require analysis was this:

https://codereview.chromium.org/1410333006/diff/1/content/common/sandbox_win.cc
File content/common/sandbox_win.cc (right):

https://codereview.chromium.org/1410333006/diff/1/content/common/sandbox_win....
content/common/sandbox_win.cc:243: return
/*base::StringPrintf(L"\\Sessions\\%lu%ls", s_session_id, object)*/ L"";
String printing - prepending logon session to object path.



If ASCIIToUTF16 or UTF8toUTF16 were to generate bad strings then those might be
able to get through to one of these functions but hand checking of these
functions suggests that they cannot generate bad UTF16 strings.

[cpu_(ooo_6.6-7.5), 2015-11-05 00:43:09]

lgtm

[cpu_(ooo_6.6-7.5), 2015-11-05 00:43:12]

The CQ bit was checked by cpu@chromium.org

[commit-bot: I haz the power, 2015-11-05 00:44:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1411683009/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1411683009/1

[commit-bot: I haz the power, 2015-11-05 01:05:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-11-05 01:06:33]

Patchset 1 (id:??) landed as
https://crrev.com/4f5d484cfe4e2bb268dd479b6fbc23963aac564b
Cr-Commit-Position: refs/heads/master@{#357964}