Add SampleMap and use it in SparseHistogram

base/metrics/sample_vector_unittest.cc

 // Copyright (c) 2012 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 <vector>
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/bucket_ranges.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sample_vector.h"
@@ skipping 150 matching lines @@
   EXPECT_DEATH(samples1.Add(samples2), "");
   EXPECT_DEATH(samples1.Subtract(samples2), "");
 
   // Bucket not match: [3, 5) VS [3, 6)
   samples2.Accumulate(6, -100);
   samples2.Accumulate(3, 100);
   EXPECT_DEATH(samples1.Add(samples2), "");
   EXPECT_DEATH(samples1.Subtract(samples2), "");
 }
 
+#endif
 // (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)) && GTEST_HAS_DEATH_TEST
-#endif
 
 TEST(SampleVectorIteratorTest, IterateTest) {
   BucketRanges ranges(5);
   ranges.set_range(0, 0);
   ranges.set_range(1, 1);
   ranges.set_range(2, 2);
   ranges.set_range(3, 3);
   ranges.set_range(4, 4);
 
   vector<HistogramBase::Count> counts(3);
@@ skipping 68 matching lines @@
   HistogramBase::Count count;
   EXPECT_DEATH(it->Get(&min, &max, &count), "");
 
   EXPECT_DEATH(it->Next(), "");
 
   samples.Accumulate(2, 100);
   it = samples.Iterator();
   EXPECT_FALSE(it->Done());
 }
 
+#endif
 // (!defined(NDEBUG) || defined(DCHECK_ALWAYS_ON)) && GTEST_HAS_DEATH_TEST
-#endif
 
 }  // namespace
 }  // namespace base