Add flag to enable shared x-axis for local event log visualization.

Bug: None
Change-Id: I4aea047c905aa8acbe25fd325bc92bb65b8d0826
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/132557
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#27583}
diff --git a/rtc_tools/event_log_visualizer/plot_python.h b/rtc_tools/event_log_visualizer/plot_python.h
index 61d17a0..23a0a92 100644
--- a/rtc_tools/event_log_visualizer/plot_python.h
+++ b/rtc_tools/event_log_visualizer/plot_python.h
@@ -23,10 +23,13 @@
 
 class PythonPlotCollection final : public PlotCollection {
  public:
-  PythonPlotCollection();
+  explicit PythonPlotCollection(bool shared_xaxis = false);
   ~PythonPlotCollection() override;
   void Draw() override;
   Plot* AppendNewPlot() override;
+
+ private:
+  bool shared_xaxis_;
 };
 
 }  // namespace webrtc