Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

content/renderer/input/render_widget_input_handler.cc

Index: content/renderer/input/render_widget_input_handler.cc
diff --git a/content/renderer/input/render_widget_input_handler.cc b/content/renderer/input/render_widget_input_handler.cc
index 047ba037ed313e62496b4a4bf3cb1d1850ee5964..b7d982b4d1a9657b36295e7e0aa2c2ce09dcd160 100644
--- a/content/renderer/input/render_widget_input_handler.cc
+++ b/content/renderer/input/render_widget_input_handler.cc
@@ -121,7 +121,7 @@ void LogPassiveEventListenersUma(WebInputEventResult result,
                                  WebInputEvent::DispatchType dispatch_type,
                                  double event_timestamp,
                                  const ui::LatencyInfo& latency_info) {
-  enum {
+  enum ListenerEnum {
     PASSIVE_LISTENER_UMA_ENUM_PASSIVE,
     PASSIVE_LISTENER_UMA_ENUM_UNCANCELABLE,
     PASSIVE_LISTENER_UMA_ENUM_SUPPRESSED,
@@ -132,7 +132,7 @@ void LogPassiveEventListenersUma(WebInputEventResult result,
     PASSIVE_LISTENER_UMA_ENUM_COUNT
   };
 
-  int enum_value;
+  ListenerEnum enum_value;
   switch (dispatch_type) {
     case WebInputEvent::kListenersForcedNonBlockingDueToFling:
       enum_value = PASSIVE_LISTENER_UMA_ENUM_FORCED_NON_BLOCKING_DUE_TO_FLING;