Print general usage information for event_log_analyzer

webrtc/rtc_tools/event_log_visualizer/main.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 85 matching lines @@
     "Mark the delay based bwe detector state on the total bitrate graph");
 
 int main(int argc, char* argv[]) {
   std::string program_name = argv[0];
   std::string usage =
       "A tool for visualizing WebRTC event logs.\n"
       "Example usage:\n" +
       program_name + " <logfile> | python\n" + "Run " + program_name +
       " --help for a list of command line options\n";
   rtc::FlagList::SetFlagsFromCommandLine(&argc, argv, true);
-  if (FLAG_help) {
-    rtc::FlagList::Print(nullptr, false);
+  if (argc != 2 || FLAG_help) {
+    // Print usage information.
+    std::cout << usage;
+    if (FLAG_help)
+      rtc::FlagList::Print(nullptr, false);
     return 0;
   }
 
-  if (argc != 2) {
-    // Print usage information.
-    std::cout << usage;
-    return 0;
-  }
-
   webrtc::test::SetExecutablePath(argv[0]);
   webrtc::test::InitFieldTrialsFromString(FLAG_force_fieldtrials);
 
   std::string filename = argv[1];
 
   webrtc::ParsedRtcEventLog parsed_log;
 
   if (!parsed_log.ParseFile(filename)) {
     std::cerr << "Could not parse the entire log file." << std::endl;
     std::cerr << "Proceeding to analyze the first "
@@ skipping 121 matching lines @@
         webrtc::test::ResourcePath(
             "audio_processing/conversational_speech/EN_script2_F_sp2_B1",
             "wav"),
         48000, collection->AppendNewPlot());
   }
 
   collection->Draw();
 
   return 0;
 }