Change the logic for discarding all non-histogram logs because of actions/omnibox events to truncat…

ios/chrome/today_extension/today_metrics_logger.mm

Index: ios/chrome/today_extension/today_metrics_logger.mm
diff --git a/ios/chrome/today_extension/today_metrics_logger.mm b/ios/chrome/today_extension/today_metrics_logger.mm
index a248102b5d317a45290a61e3660c36182cf4aabe..cde4862519e0bdcab32f7e583e641fb78b26e6a9 100644
--- a/ios/chrome/today_extension/today_metrics_logger.mm
+++ b/ios/chrome/today_extension/today_metrics_logger.mm
@@ -46,9 +46,6 @@ NSString* const kTodayExtensionMetricsSessionID = @"MetricsSessionID";
 // restart, this log can be written to disk for upload.
 NSString* const kTodayExtensionMetricsCurrentLog = @"MetricsCurrentLog";
 
-// Maximum number of event in a log.
-const int kMaxEventsPerLog = 1000;
-
 // Maximum age of a log.
 const int kMaxLogLifeTimeInSeconds = 86400;
 
@@ -207,9 +204,9 @@ void TodayMetricsLogger::PersistLogs() {
   [[NSUserDefaults standardUserDefaults]
       setObject:ns_encoded_log
          forKey:kTodayExtensionMetricsCurrentLog];
-  if (log_->num_events() >= kMaxEventsPerLog ||
-      (base::TimeTicks::Now() - log_->creation_time()).InSeconds() >=
-          kMaxLogLifeTimeInSeconds) {
+  log_->TruncateEvents();
+  if ((base::TimeTicks::Now() - log_->creation_time()).InSeconds() >=
+      kMaxLogLifeTimeInSeconds) {
     CreateNewLog();
   }
 }