Log the size of each of the stores and complete DB on launch and after each

components/safe_browsing_db/v4_database.h

Index: components/safe_browsing_db/v4_database.h
diff --git a/components/safe_browsing_db/v4_database.h b/components/safe_browsing_db/v4_database.h
index 9c2e40541efb72fb0f25c5265c4eb43562717200..28fa330631eff2b64ce03138b9126eb22d3ae1dc 100644
--- a/components/safe_browsing_db/v4_database.h
+++ b/components/safe_browsing_db/v4_database.h
@@ -136,6 +136,10 @@ class V4Database {
   void VerifyChecksum(
       DatabaseReadyForUpdatesCallback db_ready_for_updates_callback);
 
+  // Records the size of each of the stores managed by this database, along
+  // with the combined size of all the stores.
+  void RecordFileSizeHistograms();
+
  protected:
   V4Database(const scoped_refptr<base::SequencedTaskRunner>& db_task_runner,
              std::unique_ptr<StoreMap> store_map);