clang/win: Try to fix 64-bit build after https://codereview.chromium.org/1261953003.

BUG=505316
TBR=cpu@chromium.org

Review URL: https://codereview.chromium.org/1284533002.

Cr-Commit-Position: refs/heads/master@{#342538}

sandbox/win/src/process_mitigations_test.cc

@@ -30,6 +30,7 @@ typedef BOOL (WINAPI *GetProcessMitigationPolicyFunction)(
 
 GetProcessMitigationPolicyFunction get_process_mitigation_policy;
 
+#if !defined(_WIN64)
 bool CheckWin8DepPolicy() {
   PROCESS_MITIGATION_DEP_POLICY policy = {};
   if (!get_process_mitigation_policy(::GetCurrentProcess(), ProcessDEPPolicy,
@@ -38,6 +39,7 @@ bool CheckWin8DepPolicy() {
   }
   return policy.Enable && policy.Permanent;
 }
+#endif  // !defined(_WIN64)
 
 #if defined(NDEBUG)
 bool CheckWin8AslrPolicy() {

tools/gn/exec_process_unittest.cc

@@ -14,6 +14,10 @@
 
 namespace internal {
 
+// TODO(cjhopman): Enable these tests when windows ExecProcess handles stderr.
+// 'python' is not runnable on Windows. Adding ["cmd", "/c"] fails because
+// CommandLine does unusual reordering of args.
+#if !defined(OS_WIN)
 namespace {
 bool ExecPython(const std::string& command,
                 std::string* std_out,
@@ -35,10 +39,6 @@ bool ExecPython(const std::string& command,
 }
 }  // namespace
 
-// TODO(cjhopman): Enable these tests when windows ExecProcess handles stderr.
-// 'python' is not runnable on Windows. Adding ["cmd", "/c"] fails because
-// CommandLine does unusual reordering of args.
-#if !defined(OS_WIN)
 TEST(ExecProcessTest, TestExitCode) {
   std::string std_out, std_err;
   int exit_code;