Fix some typos.

TBR=terelius@webrtc.org

No-Try: True
Bug: None
Change-Id: I68cbaeb8bcac6d06e55018f273bb25cbca8d9aad
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/146719
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28679}
diff --git a/rtc_tools/event_log_visualizer/analyzer.h b/rtc_tools/event_log_visualizer/analyzer.h
index 2432b4d..7551ebf 100644
--- a/rtc_tools/event_log_visualizer/analyzer.h
+++ b/rtc_tools/event_log_visualizer/analyzer.h
@@ -39,7 +39,7 @@
 
   // Window and step size used for calculating moving averages, e.g. bitrate.
   // The generated data points will be |step_| microseconds apart.
-  // Only events occuring at most |window_duration_| microseconds before the
+  // Only events occurring at most |window_duration_| microseconds before the
   // current data point will be part of the average.
   int64_t window_duration_;
   int64_t step_;