Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

components/sync/engine_impl/model_type_registry.cc

 // Copyright 2014 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.
 
 #include "components/sync/engine_impl/model_type_registry.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 104 matching lines @@
 
   // Initialize Processor -> Worker communication channel.
   type_processor->ConnectSync(base::MakeUnique<CommitQueueProxy>(
       worker_ptr->AsWeakPtr(), base::ThreadTaskRunnerHandle::Get()));
 
   // Attempt migration if necessary.
   if (do_migration) {
     // TODO(crbug.com/658002): Store a pref before attempting migration
     // indicating that it was attempted so we can avoid failure loops.
     if (uss_migrator_.Run(type, user_share_, worker_ptr)) {
+      // TODO(wychen): enum uma should be strongly typed. crbug.com/661401
       UMA_HISTOGRAM_ENUMERATION("Sync.USSMigrationSuccess",
                                 ModelTypeToHistogramInt(type),
-                                MODEL_TYPE_COUNT);
+                                static_cast<int>(MODEL_TYPE_COUNT));
       // If we succesfully migrated, purge the directory of data for the type.
       // Purging removes the directory's local copy of the data only.
       directory()->PurgeEntriesWithTypeIn(ModelTypeSet(type), ModelTypeSet(),
                                           ModelTypeSet());
     } else {
+      // TODO(wychen): enum uma should be strongly typed. crbug.com/661401
       UMA_HISTOGRAM_ENUMERATION("Sync.USSMigrationFailure",
                                 ModelTypeToHistogramInt(type),
-                                MODEL_TYPE_COUNT);
+                                static_cast<int>(MODEL_TYPE_COUNT));
     }
   }
 
   // We want to check that we haven't accidentally enabled both the non-blocking
   // and directory implementations for a given model type. This is true even if
   // migration fails; our fallback in this case is to do an initial GetUpdates,
   // not to use the directory implementation.
   DCHECK(Intersection(GetEnabledDirectoryTypes(), GetEnabledNonBlockingTypes())
              .Empty());
 }
@@ skipping 207 matching lines @@
 
 ModelTypeSet ModelTypeRegistry::GetEnabledNonBlockingTypes() const {
   ModelTypeSet enabled_non_blocking_types;
   for (const auto& worker : model_type_workers_) {
     enabled_non_blocking_types.Put(worker->GetModelType());
   }
   return enabled_non_blocking_types;
 }
 
 }  // namespace syncer