Update from https://crrev.com/333737

base/metrics/sample_vector_unittest.cc

Index: base/metrics/sample_vector_unittest.cc
diff --git a/base/metrics/sample_vector_unittest.cc b/base/metrics/sample_vector_unittest.cc
index 9c7ba9623333e22a2e77ed2ed4891dcff55d07e5..fd4237666997ea96150fe1c4c4ab18b76d3918f6 100644
--- a/base/metrics/sample_vector_unittest.cc
+++ b/base/metrics/sample_vector_unittest.cc
@@ -2,16 +2,15 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/metrics/sample_vector.h"
+
 #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"
 #include "testing/gtest/include/gtest/gtest.h"
 
-using std::vector;
-
 namespace base {
 namespace {
 
@@ -179,7 +178,7 @@ TEST(SampleVectorIteratorTest, IterateTest) {
   ranges.set_range(3, 3);
   ranges.set_range(4, 4);
 
-  vector<HistogramBase::Count> counts(3);
+  std::vector<HistogramBase::Count> counts(3);
   counts[0] = 1;
   counts[1] = 0;  // Iterator will bypass this empty bucket.
   counts[2] = 2;