Adjust guard macros around PdfiumSpanDeathTest.DanglingReference.

The test should successfully detect the death of the process
when using e.g. BRP's danlging pointer detector.

Change-Id: I844b472adb1ca3989a56922b7312100e85cf3fde
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/112415
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Tom Sepez <tsepez@chromium.org>

core/fxcrt/pdfium_span_unittest.cpp

diff --git a/core/fxcrt/pdfium_span_unittest.cpp b/core/fxcrt/pdfium_span_unittest.cpp
index e9da064..b1bfe7d 100644
--- a/core/fxcrt/pdfium_span_unittest.cpp
+++ b/core/fxcrt/pdfium_span_unittest.cpp
@@ -4,6 +4,7 @@
 
 #include <vector>
 
+#include "core/fxcrt/unowned_ptr.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/base/containers/span.h"
 
@@ -52,7 +53,7 @@
   EXPECT_DEATH(empty_span.back() += 1, ".*");
 }
 
-#if defined(ADDRESS_SANITIZER)
+#if defined(UNOWNED_PTR_DANGLING_CHECKS)
 namespace {
 
 void CreateDanglingSpan() {
@@ -68,4 +69,4 @@
 TEST(PdfiumSpanDeathTest, DanglingReference) {
   EXPECT_DEATH(CreateDanglingSpan(), ".*");
 }
-#endif  // defined(ADDRESS_SANITIZER)
+#endif  // defined(UNOWNED_PTR_DANGLING_CHECKS)