Fix includes

Fix missing include for DWORD_PTR on WIN

Change-Id: I2cc06190fa6ea9cca944a2198c95e2b56886f1f6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1729634
Auto-Submit: Carlos Caballero <carlscab@google.com>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#682987}

ipc/ipc_perftest_util.h

@@ -7,6 +7,10 @@
 
 #include <string>
 
+#if defined(OS_WIN)
+#include <windows.h>
+#endif
+
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"