Move part of metrics from chrome/common to components

chrome/browser/metrics/metrics_log_serializer_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 "base/base64.h"
 #include "base/md5.h"
 #include "base/values.h"
 #include "chrome/browser/metrics/metrics_log_serializer.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+using metrics::MetricsLogManager;
+
 namespace {
 
 const size_t kListLengthLimit = 3;
 const size_t kLogByteLimit = 1000;
 
 void SetLogText(const std::string& log_text,
                 MetricsLogManager::SerializedLog* log) {
   std::string log_text_copy = log_text;
   log->SwapLogText(&log_text_copy);
 }
@@ skipping 242 matching lines @@
   EXPECT_TRUE((*(list.end() - 1))->GetAsString(&checksum));
   checksum[0] = (checksum[0] == 'a') ? 'b' : 'a';
   EXPECT_TRUE(list.Set(2, base::Value::CreateStringValue(checksum)));
   EXPECT_EQ(3U, list.GetSize());
 
   local_list.clear();
   EXPECT_EQ(
       MetricsLogSerializer::CHECKSUM_CORRUPTION,
       MetricsLogSerializer::ReadLogsFromPrefList(list, &local_list));
 }