Add a minimum byte count to metrics log serialization

chrome/browser/metrics/metrics_log_serializer.h

 // 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.
 
 #ifndef CHROME_BROWSER_METRICS_METRICS_LOG_SERIALIZER_H_
 #define CHROME_BROWSER_METRICS_METRICS_LOG_SERIALIZER_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
@@ skipping 31 matching lines @@
       const std::vector<MetricsLogManager::SerializedLog>& logs,
       MetricsLogManager::LogType log_type) OVERRIDE;
   virtual void DeserializeLogs(
       MetricsLogManager::LogType log_type,
       std::vector<MetricsLogManager::SerializedLog>* logs) OVERRIDE;
 
  private:
   // Encodes the textual log data from |local_list| and writes it to the given
   // pref list, along with list size and checksum.  If |is_xml| is true, writes
   // the XML data from |local_list|; otherwise writes the protobuf data.
+  // Logs will be stored starting with the most recent, and working backward
+  // until at least |list_length_limit| logs and |byte_limit| bytes of logs have
+  // been stored. At least one of those two arguments must be non-zero.
   static void WriteLogsToPrefList(
       const std::vector<MetricsLogManager::SerializedLog>& local_list,
       bool is_xml,
-      size_t max_list_size,
+      size_t list_length_limit,
+      size_t byte_limit,
       base::ListValue* list);
 
   // Decodes and verifies the textual log data from |list|, populating
   // |local_list| and returning a status code.  If |is_xml| is true, populates
   // the XML data in |local_list|; otherwise populates the protobuf data.
   static LogReadStatus ReadLogsFromPrefList(
       const base::ListValue& list,
       bool is_xml,
       std::vector<MetricsLogManager::SerializedLog>* local_list);
 
   FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, EmptyLogList);
   FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, SingleElementLogList);
-  FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, OverLimitLogList);
+  FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, LongButTinyLogList);
+  FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, LongButSmallLogList);
+  FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, ShortButLargeLogList);
+  FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, LongAndLargeLogList);
   FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, SmallRecoveredListSize);
   FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, RemoveSizeFromLogList);
   FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, CorruptSizeOfLogList);
   FRIEND_TEST_ALL_PREFIXES(MetricsLogSerializerTest, CorruptChecksumOfLogList);
 
   DISALLOW_COPY_AND_ASSIGN(MetricsLogSerializer);
 };
 
 #endif  // CHROME_BROWSER_METRICS_METRICS_LOG_SERIALIZER_H_