Calculate the size of all cache entries between two points in time.

net/disk_cache/blockfile/backend_impl.h

Index: net/disk_cache/blockfile/backend_impl.h
diff --git a/net/disk_cache/blockfile/backend_impl.h b/net/disk_cache/blockfile/backend_impl.h
index 4b44ace5fd471956b4c5496ca1b2e5bf413dbb48..377f02b829187f977f84c70cf9e5caae48cded35 100644
--- a/net/disk_cache/blockfile/backend_impl.h
+++ b/net/disk_cache/blockfile/backend_impl.h
@@ -282,6 +282,11 @@ class NET_EXPORT_PRIVATE BackendImpl : public Backend {
   int DoomEntriesSince(base::Time initial_time,
                        const CompletionCallback& callback) override;
   int CalculateSizeOfAllEntries(const CompletionCallback& callback) override;
+  int CalculateSizeOfEntriesBetween(
+      base::Time initial_time,
+      base::Time end_time,
+      const CompletionCallback& callback) override;
+
   // NOTE: The blockfile Backend::Iterator::OpenNextEntry method does not modify
   // the last_used field of the entry, and therefore it does not impact the
   // eviction ranking of the entry. However, an enumeration will go through all