win/clang: Remove unused variables in 32-bit builds.

win/clang: Remove unused variables in 32-bit builds.

No inteded behavior change. Fixes:

..\..\sandbox\win\src\process_mitigations.cc(90,24) :  warning(clang): unused variable 'MEM_EXECUTE_OPTION_ENABLE' [-Wunused-variable]
      static const int MEM_EXECUTE_OPTION_ENABLE = 1;
                       ^
..\..\sandbox\win\src\service_resolver_32.cc(21,12) :  warning(clang): unused variable 'kNop' [-Wunused-const-variable]
const BYTE kNop = 0x90;
           ^
..\..\sandbox\win\src\service_resolver_32.cc(33,11) :  warning(clang): unused variable 'kMaxService' [-Wunused-const-variable]
const int kMaxService = 1000;
          ^

BUG=505319
Committed: https://crrev.com/c11e2e0b957aa01a05fb53b2fc627d73b82da3c8
Cr-Commit-Position: refs/heads/master@{#338393}

[Nico, 2015-07-10 22:40:17]

thakis@chromium.org changed reviewers:
+ wfh@chromium.org

[Will Harris, 2015-07-10 22:43:09]

lgtm... someone will inevitably complain these are gone... but we have history
:)

[Nico, 2015-07-10 22:44:17]

The CQ bit was checked by thakis@chromium.org

[commit-bot: I haz the power, 2015-07-10 22:45:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1232723002/1

[commit-bot: I haz the power, 2015-07-10 23:22:24]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-07-10 23:24:17]

Patchset 1 (id:??) landed as
https://crrev.com/c11e2e0b957aa01a05fb53b2fc627d73b82da3c8
Cr-Commit-Position: refs/heads/master@{#338393}