Make UMA_HISTOGRAM_ENUMERATION work with scoped enums.

base/metrics/histogram_unittest.nc

 // Copyright 2016 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.
 
 // This is a "No Compile Test" suite.
 // http://dev.chromium.org/developers/testing/no-compile-tests
 
 #include "base/metrics/histogram_macros.h"
 
 namespace base {
 
 #if defined(NCTEST_DIFFERENT_ENUM)  // [r"\|sample\| and \|boundary\| shouldn't be of different enums"]
 
 void WontCompile() {
   enum TypeA { A };
   enum TypeB { B };
   UMA_HISTOGRAM_ENUMERATION("", A, B);
 }
 
+#elif defined(NCTEST_NEGATIVE_ENUM_MAX)  // [r'static_assert failed "\|boundary\| is out of range of HistogramBase::Sample"']
+
+void WontCompile() {
+  // Buckets for enumeration start from 0, so a boundary < 0 is illegal.
+  enum class TypeA { A = -1 };
+  UMA_HISTOGRAM_ENUMERATION("", TypeA::A, TypeA::A);
+}
+
+#elif defined(NCTEST_ENUM_MAX_OUT_OF_RANGE)  // [r'static_assert failed "\|boundary\| is out of range of HistogramBase::Sample"']
+
+void WontCompile() {
+  // HistogramBase::Sample is an int and can't hold larger values.
+  enum class TypeA : uint32_t { A = 0xffffffff };
+  UMA_HISTOGRAM_ENUMERATION("", TypeA::A, TypeA::A);
+}
+
 #endif
 
 }  // namespace base