win: fix various warnings in minidump_system_info_writer_test.cc

win: fix various warnings in minidump_system_info_writer_test.cc

- Stack object instantiated for sizeof to avoid

d:\src\crashpad\crashpad\minidump\minidump_system_info_writer_test.cc(43) : error C2597: illegal reference to non-static member '_MINIDUMP_STRING::Buffer'

Could also just be sizeof(WCHAR) if that feels less ugly.

- narrowing cast
- potentially uninitialize variable warning

R=mark@chromium.org
BUG=crashpad:1
Committed: https://chromium.googlesource.com/crashpad/crashpad/+/38a026ffc75413c27f41fa6a233bb32b6b27c273

[Mark Mentovai, 2015-02-05 14:19:08]

https://codereview.chromium.org/886143004/diff/1/minidump/minidump_system_inf...
File minidump/minidump_system_info_writer_test.cc (right):

https://codereview.chromium.org/886143004/diff/1/minidump/minidump_system_inf...
minidump/minidump_system_info_writer_test.cc:42: MINIDUMP_STRING tmp = {0};
(void)tmp;
We should bring ALLOW_UNUSED_LOCAL into mini_chromium and use that here. It’s
more self-documenting.

[scottmg, 2015-02-05 17:01:55]

https://codereview.chromium.org/886143004/diff/1/minidump/minidump_system_inf...
File minidump/minidump_system_info_writer_test.cc (right):

https://codereview.chromium.org/886143004/diff/1/minidump/minidump_system_inf...
minidump/minidump_system_info_writer_test.cc:42: MINIDUMP_STRING tmp = {0};
(void)tmp;
On 2015/02/05 14:19:07, Mark Mentovai wrote:
> We should bring ALLOW_UNUSED_LOCAL into mini_chromium and use that here. It’s
> more self-documenting.

Done.

[Mark Mentovai, 2015-02-05 17:13:02]

LGTM with or after DEPS roll.

https://codereview.chromium.org/886143004/diff/20001/minidump/minidump_system...
File minidump/minidump_system_info_writer_test.cc (right):

https://codereview.chromium.org/886143004/diff/20001/minidump/minidump_system...
minidump/minidump_system_info_writer_test.cc:43: MINIDUMP_STRING tmp = {0};
Is the initialization required?

[scottmg, 2015-02-05 17:39:44]

https://codereview.chromium.org/886143004/diff/20001/minidump/minidump_system...
File minidump/minidump_system_info_writer_test.cc (right):

https://codereview.chromium.org/886143004/diff/20001/minidump/minidump_system...
minidump/minidump_system_info_writer_test.cc:43: MINIDUMP_STRING tmp = {0};
On 2015/02/05 17:13:02, Mark Mentovai wrote:
> Is the initialization required?

Yes, it otherwise complains that:

warning C4815: 'tmp' : zero-sized array in stack object will have no elements
(unless the object is an aggregate that has been aggregate initialized)

[scottmg, 2015-02-05 17:39:59]

Committed patchset #2 (id:20001) manually as
38a026ffc75413c27f41fa6a233bb32b6b27c273 (presubmit successful).