Add a minimum byte count to metrics log serialization

chrome/browser/metrics/metrics_log_serializer.h

Index: chrome/browser/metrics/metrics_log_serializer.h
diff --git a/chrome/browser/metrics/metrics_log_serializer.h b/chrome/browser/metrics/metrics_log_serializer.h
index 9a1e630415015ac855101cc519c9a675da161096..7e69582fac467917c18f42e73c5d25f90fd54b7f 100644
--- a/chrome/browser/metrics/metrics_log_serializer.h
+++ b/chrome/browser/metrics/metrics_log_serializer.h
@@ -49,10 +49,14 @@ class MetricsLogSerializer : public MetricsLogManager::LogSerializer {
   // 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.
+  // At most |max_list_length| logs will be stored, unless that doesn't reach
+  // |min_bytes| bytes of logs, in which case at least |min_bytes| will be
+  // 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 max_list_length,
+      size_t min_bytes,
       base::ListValue* list);
 
   // Decodes and verifies the textual log data from |list|, populating
@@ -65,7 +69,10 @@ class MetricsLogSerializer : public MetricsLogManager::LogSerializer {
 
   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);