Reland: [Sync] Record sync memory usage in histogram broken by datatypes

components/browser_sync/profile_sync_service.h

Index: components/browser_sync/profile_sync_service.h
diff --git a/components/browser_sync/profile_sync_service.h b/components/browser_sync/profile_sync_service.h
index a47fe59fbb3cafecd3a8187f8248c6c2e49bfd4b..ed8908c564de942f9ea99cbf9527f7bf1478d54c 100644
--- a/components/browser_sync/profile_sync_service.h
+++ b/components/browser_sync/profile_sync_service.h
@@ -725,6 +725,9 @@ class ProfileSyncService : public syncer::SyncServiceBase,
   // Check if previous shutdown is shutdown cleanly.
   void ReportPreviousSessionMemoryWarningCount();
 
+  // Estimates and records memory usage histograms per type.
+  void RecordMemoryUsageHistograms();
+
   // After user switches to custom passphrase encryption a set of steps needs to
   // be performed:
   //