Add HistogramTester::GetAllSamples.

base/test/histogram_tester_unittest.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 "base/test/histogram_tester.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/histogram_samples.h"
+#include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace base {
 
+using ::testing::ElementsAre;
+
 const std::string kHistogram1 = "Test1";
 const std::string kHistogram2 = "Test2";
 const std::string kHistogram3 = "Test3";
 const std::string kHistogram4 = "Test4";
 
 typedef testing::Test HistogramTesterTest;
 
 TEST_F(HistogramTesterTest, Scope) {
   // Record a histogram before the creation of the recorder.
   UMA_HISTOGRAM_BOOLEAN(kHistogram1, true);
@@ skipping 47 matching lines @@
 
   HistogramTester tester;
   UMA_HISTOGRAM_COUNTS_100(kHistogram4, 3);
 
   tester.ExpectBucketCount(kHistogram4, 2, 0);
   tester.ExpectBucketCount(kHistogram4, 3, 1);
 
   tester.ExpectTotalCount(kHistogram4, 1);
 }
 
+TEST_F(HistogramTesterTest, TestGetAllSamples) {
+  HistogramTester tester;
+  UMA_HISTOGRAM_COUNTS_100(kHistogram2, 2);
+  UMA_HISTOGRAM_COUNTS_100(kHistogram2, 3);
+  UMA_HISTOGRAM_COUNTS_100(kHistogram2, 3);
+  UMA_HISTOGRAM_COUNTS_100(kHistogram2, 5);

[Ilya Sherman, 2015/06/27 07:25:19]

nit: Might be clearer to use an UMA_HISTOGRAM_ENUMERATION or UMA_SPARSE_SLOWLY,
since those have buckets of width 1.

[twifkak, 2015/06/29 21:52:29]

Done.

+
+  EXPECT_THAT(tester.GetAllSamples(kHistogram2),
+              ElementsAre(Bucket(2, 1), Bucket(3, 2), Bucket(5, 1)));
+}
+
 }  // namespace base