Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

components/sync_bookmarks/bookmark_model_associator.cc

 // Copyright 2012 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_bookmarks/bookmark_model_associator.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 945 matching lines @@
       bookmark_model_->root_node()->sync_transaction_version();
 
   syncer::ReadTransaction trans(FROM_HERE, user_share_);
   int64_t sync_version = trans.GetModelVersion(syncer::BOOKMARKS);
   context->SetPreAssociationVersions(native_version, sync_version);
 
   if (native_version != syncer::syncable::kInvalidTransactionVersion) {
     if (native_version == sync_version) {
       context->set_native_model_sync_state(IN_SYNC);
     } else {
+      // TODO(wychen): enum uma should be strongly typed. crbug.com/661401
       UMA_HISTOGRAM_ENUMERATION("Sync.LocalModelOutOfSync",
                                 ModelTypeToHistogramInt(syncer::BOOKMARKS),
-                                syncer::MODEL_TYPE_COUNT);
+                                static_cast<int>(syncer::MODEL_TYPE_COUNT));
 
       // Clear version on bookmark model so that we only report error once.
       bookmark_model_->SetNodeSyncTransactionVersion(
           bookmark_model_->root_node(),
           syncer::syncable::kInvalidTransactionVersion);
 
       // If the native version is higher, there was a sync persistence failure,
       // and we need to delay association until after a GetUpdates.
       if (native_version > sync_version) {
         context->set_native_model_sync_state(AHEAD);
         std::string message = base::StringPrintf(
             "Native version (%" PRId64 ") does not match sync version (%"
                 PRId64 ")",
             native_version,
             sync_version);
         return syncer::SyncError(FROM_HERE,
                                  syncer::SyncError::PERSISTENCE_ERROR,
                                  message,
                                  syncer::BOOKMARKS);
       } else {
         context->set_native_model_sync_state(BEHIND);
       }
     }
   }
   return syncer::SyncError();
 }
 
 }  // namespace sync_bookmarks