Add support for visualizing event logs without normalizing time.

Bug: webrtc:9299
Change-Id: Icdc4cba14f143cedb7c35347dd9711ab13f975d8
Reviewed-on: https://webrtc-review.googlesource.com/77820
Commit-Queue: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#23392}
diff --git a/rtc_tools/event_log_visualizer/main.cc b/rtc_tools/event_log_visualizer/main.cc
index 221b040..802633c 100644
--- a/rtc_tools/event_log_visualizer/main.cc
+++ b/rtc_tools/event_log_visualizer/main.cc
@@ -151,6 +151,10 @@
             false,
             "Print triage alerts, i.e. a list of potential problems.");
 
+DEFINE_bool(normalize_time,
+            true,
+            "Normalize the log timestamps so that the call starts at time 0.");
+
 void SetAllPlotFlags(bool setting);
 
 
@@ -227,7 +231,7 @@
               << std::endl;
   }
 
-  webrtc::EventLogAnalyzer analyzer(parsed_log);
+  webrtc::EventLogAnalyzer analyzer(parsed_log, FLAG_normalize_time);
   std::unique_ptr<webrtc::PlotCollection> collection(
       new webrtc::PythonPlotCollection());