Don't use LOG_END timestamp to compute RtcEventLog duration.

webrtc/tools/event_log_visualizer/analyzer.cc

Index: webrtc/tools/event_log_visualizer/analyzer.cc
diff --git a/webrtc/tools/event_log_visualizer/analyzer.cc b/webrtc/tools/event_log_visualizer/analyzer.cc
index ec569990224d2a9d7e951e3e06d24793e98c06e3..c0aae6e636d4743bb068ae4d30fe0f7d30dceaf6 100644
--- a/webrtc/tools/event_log_visualizer/analyzer.cc
+++ b/webrtc/tools/event_log_visualizer/analyzer.cc
@@ -130,7 +130,9 @@ EventLogAnalyzer::EventLogAnalyzer(const ParsedRtcEventLog& log)
     if (event_type != ParsedRtcEventLog::VIDEO_RECEIVER_CONFIG_EVENT &&
         event_type != ParsedRtcEventLog::VIDEO_SENDER_CONFIG_EVENT &&
         event_type != ParsedRtcEventLog::AUDIO_RECEIVER_CONFIG_EVENT &&
-        event_type != ParsedRtcEventLog::AUDIO_SENDER_CONFIG_EVENT) {
+        event_type != ParsedRtcEventLog::AUDIO_SENDER_CONFIG_EVENT &&
+        event_type != ParsedRtcEventLog::LOG_START &&
+        event_type != ParsedRtcEventLog::LOG_END) {
       uint64_t timestamp = parsed_log_.GetTimestamp(i);
       first_timestamp = std::min(first_timestamp, timestamp);
       last_timestamp = std::max(last_timestamp, timestamp);