Track how many pages trigger fallback strategies in GC

src/heap/store-buffer.cc

Index: src/heap/store-buffer.cc
diff --git a/src/heap/store-buffer.cc b/src/heap/store-buffer.cc
index dec11daa90674b922d1a5510abd637323c08d654..b21bf27c13966184abec0cbec5d454c5ed5c7e4d 100644
--- a/src/heap/store-buffer.cc
+++ b/src/heap/store-buffer.cc
@@ -197,6 +197,8 @@ void StoreBuffer::ExemptPopularPages(int prime_sample_step, int threshold) {
   }
   if (created_new_scan_on_scavenge_pages) {
     Filter(MemoryChunk::SCAN_ON_SCAVENGE);
+    heap_->isolate()->CountUsage(
+        v8::Isolate::UseCounterFeature::kStoreBufferOverflow);
   }
   old_buffer_is_filtered_ = true;
 }