[memory-infra] Fix base_unittests on CFI bots

base/trace_event/memory_dump_scheduler.cc

Index: base/trace_event/memory_dump_scheduler.cc
diff --git a/base/trace_event/memory_dump_scheduler.cc b/base/trace_event/memory_dump_scheduler.cc
index eaa8d63661ca6d7bad289330cfa21f775a1ee07f..df4d1353d9c3be3185ea6ef68c873a3fb7220007 100644
--- a/base/trace_event/memory_dump_scheduler.cc
+++ b/base/trace_event/memory_dump_scheduler.cc
@@ -282,8 +282,11 @@ void MemoryDumpScheduler::PollingTriggerState::ResetTotals() {
     // Set threshold to 1% of total system memory.
     SystemMemoryInfoKB meminfo;
     bool res = GetSystemMemoryInfo(&meminfo);
-    if (res)
-      memory_increase_threshold = (meminfo.total / 100) * 1024;
+    if (res) {
+      memory_increase_threshold =
+          (static_cast<int64_t>(meminfo.total) / 100) * 1024;
+    }
+    DCHECK_GT(memory_increase_threshold, 0u);
 #endif
   }