Pass label and plot style to the TimeSeries' constructor.

webrtc/tools/event_log_visualizer/plot_base.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 53 matching lines @@
       max_value = std::max(max_value, point.y);
     }
   }
   SetYAxis(min_value, max_value, label, bottom_margin, top_margin);
 }
 
 void Plot::SetTitle(std::string title) {
   title_ = title;
 }
 
+TimeSeries* Plot::AddTimeSeries(const char* label, PlotStyle style) {
+  series_list_.emplace_back(label, style);
+  return &series_list_.back();
+}
+
+TimeSeries* Plot::AddTimeSeries(const std::string& label, PlotStyle style) {
+  series_list_.emplace_back(label, style);
+  return &series_list_.back();
+}
+
 }  // namespace plotting
 }  // namespace webrtc