[Sync] Implement EstimateMemoryUsage for SharedModelTypeProcessor and ModelTypeWorker

components/sync/engine_impl/worker_entity_tracker.cc

Index: components/sync/engine_impl/worker_entity_tracker.cc
diff --git a/components/sync/engine_impl/worker_entity_tracker.cc b/components/sync/engine_impl/worker_entity_tracker.cc
index 67f2aa945f044b7822717188aa63a49eca504edd..14629755a6b2de2c35c137dda42f010a479b835d 100644
--- a/components/sync/engine_impl/worker_entity_tracker.cc
+++ b/components/sync/engine_impl/worker_entity_tracker.cc
@@ -8,6 +8,7 @@
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
+#include "base/trace_event/memory_usage_estimator.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/base/time.h"
 #include "components/sync/syncable/syncable_util.h"
@@ -177,6 +178,17 @@ void WorkerEntityTracker::ClearEncryptedUpdate() {
   encrypted_update_.reset();
 }
 
+size_t WorkerEntityTracker::EstimateMemoryUsage() const {
+  using base::trace_event::EstimateMemoryUsage;
+  size_t memory_usage = 0;
+  memory_usage += EstimateMemoryUsage(client_tag_hash_);
+  memory_usage += EstimateMemoryUsage(id_);
+  memory_usage += EstimateMemoryUsage(pending_commit_);
+  memory_usage += EstimateMemoryUsage(pending_commit_specifics_hash_);
+  memory_usage += EstimateMemoryUsage(encrypted_update_);
+  return memory_usage;
+}
+
 bool WorkerEntityTracker::IsInConflict() const {
   if (!HasPendingCommit())
     return false;