Add counter for new shared/array buffers that fail to allocate space.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index e10b4a1edaf454cda22d670cc2dd3411425e47df..2901840af92fbe0b1cd995ba1129a4cb4024befa 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -19485,7 +19485,12 @@ bool JSArrayBuffer::SetupAllocatingData(Handle<JSArrayBuffer> array_buffer,
       data = isolate->array_buffer_allocator()->AllocateUninitialized(
           allocated_length);
     }
-    if (data == NULL) return false;
+    if (data == NULL) {
+      isolate->counters()->array_buffer_new_size_failures()->AddSample(
+          sizeof(uint64_t) * kBitsPerByte -
+          base::bits::CountLeadingZeros64(allocated_length));
+      return false;
+    }
   } else {
     data = NULL;
   }