improve grammar in comment

src/heap/gc-tracer.cc

Index: src/heap/gc-tracer.cc
diff --git a/src/heap/gc-tracer.cc b/src/heap/gc-tracer.cc
index 2b1f06acd7dbf1d54f8a2ca0bb96240e467a9adc..e11ee0f941e10778b8e909aa8d29243a894ecb53 100644
--- a/src/heap/gc-tracer.cc
+++ b/src/heap/gc-tracer.cc
@@ -334,7 +334,7 @@ void GCTracer::SampleAllocation(double current_ms,
     return;
   }
   // This assumes that counters are unsigned integers so that the subtraction
-  // below works even if the new counter is less then the old counter.
+  // below works even if the new counter is less than the old counter.
   size_t new_space_allocated_bytes =
       new_space_counter_bytes - new_space_allocation_counter_bytes_;
   size_t old_generation_allocated_bytes =