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

components/sync/driver/directory_data_type_controller.cc

Index: components/sync/driver/directory_data_type_controller.cc
diff --git a/components/sync/driver/directory_data_type_controller.cc b/components/sync/driver/directory_data_type_controller.cc
index a03ee3dd17c026ff9ef07a88933505883b7e9674..c08364360f6c59385dd616cdc6ac109ec2ff4466 100644
--- a/components/sync/driver/directory_data_type_controller.cc
+++ b/components/sync/driver/directory_data_type_controller.cc
@@ -9,6 +9,7 @@
 
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "components/sync/base/data_type_histogram.h"
 #include "components/sync/driver/sync_service.h"
 #include "components/sync/engine/model_type_configurer.h"
 #include "components/sync/syncable/syncable_read_transaction.h"
@@ -83,6 +84,14 @@ void DirectoryDataTypeController::GetStatusCounters(
   callback.Run(type(), counters);
 }
 
+void DirectoryDataTypeController::RecordMemoryUsageHistogram() {
+  syncer::syncable::Directory* directory =
+      sync_client_->GetSyncService()->GetUserShare()->directory.get();
+  size_t memory_usage = directory->EstimateMemoryUsageByType(type());
+  SyncRecordMemoryKbHistogram("Sync.ModelTypeMemoryKB.", type(),

[Patrick Noland, 2017/06/19 23:34:52]

Can you make "Sync.ModelTypeMemoryKB." a constant? Or maybe make a helper
function that also does the division by 1024?

[pavely, 2017/06/19 23:53:37]

Done.

+                              memory_usage / 1024);
+}
+
 // static
 std::unique_ptr<base::ListValue>
 DirectoryDataTypeController::GetAllNodesForTypeFromDirectory(