Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

components/sync/driver/startup_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/startup_controller.h"
 
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 168 matching lines @@
     return;
   }
 
   if (!start_engine_time_.is_null())
     return;
 
   DVLOG(2) << "Data type requesting sync startup: " << ModelTypeToString(type);
   // Measure the time spent waiting for init and the type that triggered it.
   // We could measure the time spent deferred on a per-datatype basis, but
   // for now this is probably sufficient.
+  // TODO(wychen): enum uma should be strongly typed. crbug.com/661401
   UMA_HISTOGRAM_ENUMERATION("Sync.Startup.TypeTriggeringInit",
-                            ModelTypeToHistogramInt(type), MODEL_TYPE_COUNT);
+                            ModelTypeToHistogramInt(type),
+                            static_cast<int>(MODEL_TYPE_COUNT));
   if (!start_up_time_.is_null()) {
     RecordTimeDeferred();
     UMA_HISTOGRAM_ENUMERATION("Sync.Startup.DeferredInitTrigger",
                               TRIGGER_DATA_TYPE_REQUEST, MAX_TRIGGER_VALUE);
   }
   received_start_request_ = true;
   TryStart();
 }
 
 }  // namespace syncer