[Windows Sandbox Tests] Process Mitigations.

sandbox/win/tests/integration_tests/hooking_dll.cc

Index: sandbox/win/tests/integration_tests/hooking_dll.cc
diff --git a/sandbox/win/tests/integration_tests/hooking_dll.cc b/sandbox/win/tests/integration_tests/hooking_dll.cc
index f275ae6e940208bc65b71ddeced35199cb7827a7..9fe664d8f775833c6a22778ae7eae4e3c4ab1690 100644
--- a/sandbox/win/tests/integration_tests/hooking_dll.cc
+++ b/sandbox/win/tests/integration_tests/hooking_dll.cc
@@ -5,7 +5,6 @@
 #include <stdio.h>
 #include <windows.h>
 
-#define _DLL_EXPORTING
 #include "integration_tests_common.h"
 
 // This data section creates a common area that is accessible
@@ -54,10 +53,10 @@ BOOL WINAPI DllMain(HINSTANCE instance, DWORD reason, LPVOID reserved) {
   if (reason == DLL_PROCESS_ATTACH) {
     // The testing process should have set up this named event already
     // (if the test needs this event to be signaled).
-    event = ::OpenEventW(EVENT_MODIFY_STATE, FALSE, g_hook_event);
+    event = ::OpenEventW(EVENT_MODIFY_STATE, FALSE, sandbox::g_hook_event);
   }
 
-  if (reason == DLL_PROCESS_DETACH)
+  if (reason == DLL_PROCESS_DETACH && event != nullptr)
     ::CloseHandle(event);
 
   return TRUE;