check the return value of base::SysInfo::MaxSharedMemorySize().

base/sys_info_unittest.cc

Index: base/sys_info_unittest.cc
diff --git a/base/sys_info_unittest.cc b/base/sys_info_unittest.cc
index edabdb5c6bf0cb949841a0be3e09f79fae665ea1..887f7d1ade4f90bdcaeba8a1eee9f6a95290e94c 100644
--- a/base/sys_info_unittest.cc
+++ b/base/sys_info_unittest.cc
@@ -9,6 +9,13 @@
 
 typedef PlatformTest SysInfoTest;
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+TEST_F(SysInfoTest, MaxSharedMemorySize) {
+  // We aren't actually testing that it's correct, just that it's sane.
+  EXPECT_GT(base::SysInfo::MaxSharedMemorySize(), 0u);
+}
+#endif
+
 TEST_F(SysInfoTest, NumProcs) {
   // We aren't actually testing that it's correct, just that it's sane.
   EXPECT_GE(base::SysInfo::NumberOfProcessors(), 1);