Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

components/sync/driver/async_directory_type_controller.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/driver/async_directory_type_controller.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
@@ skipping 189 matching lines @@
     // Start failed.
     StopModels();
     RecordStartFailure(start_result);
   }
 
   start_callback_.Run(start_result, local_merge_result, syncer_merge_result);
 }
 
 void AsyncDirectoryTypeController::RecordStartFailure(ConfigureResult result) {
   DCHECK(CalledOnValidThread());
+  // TODO(wychen): enum uma should be strongly typed. crbug.com/661401
   UMA_HISTOGRAM_ENUMERATION("Sync.DataTypeStartFailures",
-                            ModelTypeToHistogramInt(type()), MODEL_TYPE_COUNT);
+                            ModelTypeToHistogramInt(type()),
+                            static_cast<int>(MODEL_TYPE_COUNT));
 #define PER_DATA_TYPE_MACRO(type_str)                                    \
   UMA_HISTOGRAM_ENUMERATION("Sync." type_str "ConfigureFailure", result, \
                             MAX_CONFIGURE_RESULT);
   SYNC_DATA_TYPE_HISTOGRAM(type());
 #undef PER_DATA_TYPE_MACRO
 }
 
 void AsyncDirectoryTypeController::DisableImpl(const SyncError& error) {
   DCHECK(CalledOnValidThread());
   if (!model_load_callback_.is_null()) {
@@ skipping 41 matching lines @@
 std::unique_ptr<DataTypeErrorHandler>
 AsyncDirectoryTypeController::CreateErrorHandler() {
   DCHECK(CalledOnValidThread());
   return base::MakeUnique<DataTypeErrorHandlerImpl>(
       base::ThreadTaskRunnerHandle::Get(), dump_stack_,
       base::Bind(&AsyncDirectoryTypeController::DisableImpl,
                  base::AsWeakPtr(this)));
 }
 
 }  // namespace syncer