clang/win: Let some chromium_code targets build with -Wextra.

base/win/event_trace_provider.h

Index: base/win/event_trace_provider.h
diff --git a/base/win/event_trace_provider.h b/base/win/event_trace_provider.h
index a87cb9c1cfd860d3898db1183fd63985bcd2cb6b..0775fafb652692870f151bbe210e75535ae548d2 100644
--- a/base/win/event_trace_provider.h
+++ b/base/win/event_trace_provider.h
@@ -67,7 +67,7 @@ template <size_t N> class EtwMofEvent: public EtwMofEventBase<N> {
     header.Flags = WNODE_FLAG_TRACED_GUID | WNODE_FLAG_USE_MOF_PTR;
   }
 
-  void SetField(int field, size_t size, const void *data) {
+  void SetField(size_t field, size_t size, const void* data) {
     // DCHECK(field < N);
     if ((field < N) && (size <= std::numeric_limits<uint32_t>::max())) {
       fields[field].DataPtr = reinterpret_cast<ULONG64>(data);