UserEvent proto exploration for Translate use case.

components/sync/protocol/proto_memory_estimations.cc

 // Copyright (c) 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Keep this file in sync with the .proto files in this directory.
 
 #include "components/sync/protocol/proto_memory_estimations.h"
 
 #include <string>
 
@@ skipping 29 matching lines @@
   // Types derived from MessageLite (i.e. protos)
   template <class P, class F>
   typename std::enable_if<
       std::is_base_of<google::protobuf::MessageLite, F>::value>::type
   Visit(const P&, const char* field_name, const F& field) {
     using base::trace_event::EstimateMemoryUsage;
     // All object fields are dynamically allocated.
     memory_usage_ += sizeof(F) + EstimateMemoryUsage(field);
   }
 
-  // Integral types
+  // Arithmetic types
   template <class P, class F>
-  typename std::enable_if<std::is_integral<F>::value>::type
+  typename std::enable_if<std::is_arithmetic<F>::value>::type
   Visit(const P&, const char* field_name, const F& field) {
-    // Integral fields (integers, floats & bool) don't allocate.
+    // Arithmetic fields (integers, floats & bool) don't allocate.
   }
 
   // std::string
   template <class P>
   void Visit(const P&, const char* field_name, const std::string& field) {
     using base::trace_event::EstimateMemoryUsage;
     // All strings are of type ArenaStringPtr, which essentially
     // is std::string*.
     memory_usage_ += sizeof(std::string) + EstimateMemoryUsage(field);
   }
 
   // RepeatedPtrField
   template <class P, class F>
   void Visit(const P&,
              const char* field_name,
              const google::protobuf::RepeatedPtrField<F>& fields) {
     using base::trace_event::EstimateMemoryUsage;
     // Can't use RepeatedPtrField::SpaceUsedExcludingSelf() because it will
     // end up calling undefined TypeHandler::SpaceUsed() method.
     memory_usage_ += fields.Capacity() ? sizeof(void*) : 0;  // header
     memory_usage_ += fields.Capacity() * sizeof(void*);
     for (const auto& field : fields) {
       memory_usage_ += sizeof(F) + EstimateMemoryUsage(field);
     }
   }
 
-  // RepeatedField<integral type>
+  // RepeatedField<arithmetic type>
   template <class P, class F>
-  typename std::enable_if<std::is_integral<F>::value>::type Visit(
+  typename std::enable_if<std::is_arithmetic<F>::value>::type Visit(
       const P&,
       const char* field_name,
       const google::protobuf::RepeatedField<F>& fields) {
     memory_usage_ += fields.SpaceUsedExcludingSelf();
-    // Integral fields (integers, floats & bool) don't allocate, so no
-    // point in iterating over |fields|.
+    // Arithmetic fields (integers, floats & bool) don't allocate, so no point
+    // in iterating over |fields|.
   }
 
   // RepeatedField<std::string>
   template <class P>
   void Visit(const P&,
              const char* field_name,
              const google::protobuf::RepeatedField<std::string>& fields) {
     using base::trace_event::EstimateMemoryUsage;
     memory_usage_ += fields.SpaceUsedExcludingSelf();
     for (const auto& field : fields) {
@@ skipping 22 matching lines @@
   template size_t EstimateMemoryUsage<Proto>(const Proto&);
 
 INSTANTIATE(AttachmentMetadata)
 INSTANTIATE(DataTypeContext)
 INSTANTIATE(EntityMetadata)
 INSTANTIATE(EntitySpecifics)
 INSTANTIATE(ModelTypeState)
 INSTANTIATE(UniquePosition)
 
 }  // namespace sync_pb