Use stricter type checking in UMA_HISTOGRAM_ENUMERATION

ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm

Index: ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm
diff --git a/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm b/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm
index a776d8785a661050fca6702e0ddf82ca06a4f92c..ae11ce9ce4bed8dd337574cb0178b6b5dc9ebdc6 100644
--- a/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm
+++ b/ios/chrome/browser/ui/contextual_search/contextual_search_metrics.mm
@@ -27,7 +27,7 @@ using ContextualSearch::StateChangeReason;
 
 #define LOGGED_UMA_HISTOGRAM_ENUMERATION(name, sample, boundary, log_level) \
   {                                                                         \
-    int evaluated_sample = sample;                                          \
+    auto evaluated_sample = static_cast<decltype(boundary)>(sample);        \
     VLOG_UMA_HISTOGRAM_ENUMERATION(log_level, name, evaluated_sample);      \
     UMA_HISTOGRAM_ENUMERATION(name, evaluated_sample, boundary);            \
   }