Don't report array buffer allocations less than 1 Mb.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index f40dc1e007d58b0ddc36cf753bdbedaf53fbb4c5..7c65a8ce244ad6ae0b37a337d236ca494e6e555a 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -19561,8 +19561,9 @@ bool JSArrayBuffer::SetupAllocatingData(Handle<JSArrayBuffer> array_buffer,
   // Prevent creating array buffers when serializing.
   DCHECK(!isolate->serializer_enabled());
   if (allocated_length != 0) {
-    isolate->counters()->array_buffer_big_allocations()->AddSample(
-        ConvertToMb(allocated_length));
+    if (allocated_length >= MB)
+      isolate->counters()->array_buffer_big_allocations()->AddSample(
+          ConvertToMb(allocated_length));
     if (initialize) {
       data = isolate->array_buffer_allocator()->Allocate(allocated_length);
     } else {