Skip oversized logs when persisting logs instead of discarding them.

components/metrics/persisted_logs.h

 // Copyright 2014 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 COMPONENTS_METRICS_PERSISTED_LOGS_H_
 #define COMPONENTS_METRICS_PERSISTED_LOGS_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 33 matching lines @@
 
   // Constructs a PersistedLogs that stores data in |local_state| under the
   // preference |pref_name| and also reads from legacy pref |old_pref_name|.
   // Calling code is responsible for ensuring that the lifetime of |local_state|
   // is longer than the lifetime of PersistedLogs.
   //
   // When saving logs to disk, stores either the first |min_log_count| logs, or
   // at least |min_log_bytes| bytes of logs, whichever is greater.
   //
   // If the optional |max_log_size| parameter is non-zero, all logs larger than
-  // that limit will be dropped before logs are written to disk.
+  // that limit will be skipped when writing to disk.
   PersistedLogs(PrefService* local_state,
                 const char* pref_name,
                 const char* old_pref_name,
                 size_t min_log_count,
                 size_t min_log_bytes,
                 size_t max_log_size);
   ~PersistedLogs();
 
   // Write list to storage.
-  void SerializeLogs();
+  void SerializeLogs() const;
 
   // Reads the list from the preference.
   LogReadStatus DeserializeLogs();
 
   // Adds a log to the list.
   void StoreLog(const std::string& log_data);
 
   // Stages the most recent log.  The staged_log will remain the same even if
   // additional logs are added.
   void StageLog();
@@ skipping 33 matching lines @@
   }
 
   // The number of elements currently stored.
   size_t size() const { return list_.size(); }
 
   // True if there are no stored logs.
   bool empty() const { return list_.empty(); }
 
  private:
   // Writes the list to the ListValue.
-  void WriteLogsToPrefList(base::ListValue* list);
+  void WriteLogsToPrefList(base::ListValue* list) const;
 
   // Reads the list from the ListValue.
   LogReadStatus ReadLogsFromPrefList(const base::ListValue& list);
 
   // Reads the list from the old pref's ListValue.
   // TODO(asvitkine): Remove the old pref in M39.
   LogReadStatus ReadLogsFromOldPrefList(const base::ListValue& list);
 
   // A weak pointer to the PrefService object to read and write the preference
   // from.  Calling code should ensure this object continues to exist for the
@@ skipping 46 matching lines @@
   // and current) and a client might store them in either order, so it's
   // not necessarily the case that the provisional store is the last store.
   int last_provisional_store_index_;
 
   DISALLOW_COPY_AND_ASSIGN(PersistedLogs);
 };
 
 }  // namespace metrics
 
 #endif  // COMPONENTS_METRICS_PERSISTED_LOGS_H_