Add HistogramTester::GetAllSamples.

base/test/histogram_tester_unittest.cc

Index: base/test/histogram_tester_unittest.cc
diff --git a/base/test/histogram_tester_unittest.cc b/base/test/histogram_tester_unittest.cc
index e26828c01d3cd984a74fd6a50937c19c5413d17a..d40128580fa384e780bc7d2879dc189912715575 100644
--- a/base/test/histogram_tester_unittest.cc
+++ b/base/test/histogram_tester_unittest.cc
@@ -7,10 +7,13 @@
 #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";
@@ -78,4 +81,15 @@ TEST_F(HistogramTesterTest, TestBucketsSampleWithScope) {
   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