Use swap instead of copy in RtcHistogram::GetAndReset.

webrtc/system_wrappers/source/metrics_unittest.cc

 /*
  *  Copyright (c) 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 40 matching lines @@
   EXPECT_EQ(1, metrics::NumEvents(kName, kSample));
 }
 
 TEST_F(MetricsTest, RtcHistogramEnumeration_AddSample) {
   const std::string kName = "Enumeration";
   RTC_HISTOGRAM_ENUMERATION(kName, kSample, kSample + 1);
   EXPECT_EQ(1, metrics::NumSamples(kName));
   EXPECT_EQ(1, metrics::NumEvents(kName, kSample));
 }
 
+TEST_F(MetricsTest, RtcHistogramBoolean_AddSample) {
+  const std::string kName = "Boolean";
+  const int kSample = 0;
+  RTC_HISTOGRAM_BOOLEAN(kName, kSample);
+  EXPECT_EQ(1, metrics::NumSamples(kName));
+  EXPECT_EQ(1, metrics::NumEvents(kName, kSample));
+}
+
 TEST_F(MetricsTest, RtcHistogramCountsSparse_AddSample) {
   const std::string kName = "CountsSparse100";
   RTC_HISTOGRAM_COUNTS_SPARSE_100(kName, kSample);
   EXPECT_EQ(1, metrics::NumSamples(kName));
   EXPECT_EQ(1, metrics::NumEvents(kName, kSample));
 }
 
 TEST_F(MetricsTest, RtcHistogramCounts_AddSample) {
   const std::string kName = "Counts100";
   RTC_HISTOGRAM_COUNTS_100(kName, kSample);
@@ skipping 39 matching lines @@
 }
 
 #if RTC_DCHECK_IS_ON && GTEST_HAS_DEATH_TEST && !defined(WEBRTC_ANDROID)
 TEST_F(MetricsTest, RtcHistogram_FailsForNonConstantName) {
   AddSample("ConstantName1", kSample);
   EXPECT_DEATH(AddSample("NotConstantName1", kSample), "");
 }
 #endif
 
 }  // namespace webrtc