Make BattOr agent properly handle EOF

tools/battor_agent/battor_agent_bin.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file provides a thin binary wrapper around the BattOr Agent
 // library. This binary wrapper provides a means for non-C++ tracing
 // controllers, such as Telemetry and Android Systrace, to issue high-level
 // tracing commands to the BattOr through an interactive shell.
 //
 // Example usage of how an external trace controller might use this binary:
@@ skipping 173 matching lines @@
     } else if (cmd.find("RecordClockSyncMarker") != std::string::npos) {
       std::vector<std::string> tokens = TokenizeString(cmd);
       if (tokens.size() != 2 || tokens[0] != "RecordClockSyncMarker") {
         std::cout << "Invalid RecordClockSyncMarker command." << endl;
         std::cout << kUsage << endl;
         PostRunNextCommand();
         return;
       }
 
       RecordClockSyncMarker(tokens[1]);
-    } else if (cmd == "Exit") {
+    } else if (cmd == "Exit" || std::cin.eof()) {
       ui_thread_message_loop_.task_runner()->PostTask(
           FROM_HERE, ui_thread_run_loop_.QuitClosure());
     } else {
       std::cout << kUsage << endl;
       PostRunNextCommand();
     }
   }
 
   void PostRunNextCommand() {
     ui_thread_message_loop_.task_runner()->PostTask(
@@ skipping 101 matching lines @@
 };
 
 }  // namespace battor
 
 int main(int argc, char* argv[]) {
   base::AtExitManager exit_manager;
   base::CommandLine::Init(argc, argv);
   battor::BattOrAgentBin bin;
   return bin.Run(argc, argv);
 }