Move StatisticsRecorder out of histogram.cc/h for further refactoring.

net/socket_stream/socket_stream_metrics_unittest.cc

 // Copyright (c) 2011 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 "net/socket_stream/socket_stream_metrics.h"
 
 #include "base/basictypes.h"
 #include "base/metrics/histogram.h"
+#include "base/metrics/statistics_recorder.h"
 #include "googleurl/src/gurl.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "testing/platform_test.h"
 
 using base::Histogram;
 using base::StatisticsRecorder;
 
 namespace net {
 
 TEST(SocketStreamMetricsTest, ProtocolType) {
@@ skipping 176 matching lines @@
 
   // SentCounts.
   ASSERT_TRUE(StatisticsRecorder::FindHistogram(
       "Net.SocketStream.SentCounts", &histogram));
   EXPECT_EQ(Histogram::kUmaTargetedHistogramFlag, histogram->flags());
   histogram->SnapshotSample(&sample);
   EXPECT_EQ(3, sample.sum() - original_sent_counts);  // 3 write requests.
 }
 
 }  // namespace net