[remoting start-host] Make --name optional, and other tweaks.

remoting/host/setup/start_host_main.cc

 // Copyright (c) 2012 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.
 
 #include "remoting/host/setup/start_host_main.h"
 
 #include <stddef.h>
 #include <stdio.h>
 
 #include "base/at_exit.h"
@@ skipping 139 matching lines @@
 
 #if defined(OS_WIN)
   // The tool must be run elevated on Windows so the host has access to the
   // directories used to store the configuration JSON files.
   if (!remoting::IsProcessElevated()) {
     fprintf(stderr, "Error: %s must be run as an elevated process.", argv[0]);
     return 1;
   }
 #endif  // defined(OS_WIN)
 
-  if (host_name.empty()) {
+  if (command_line->HasSwitch("help") || command_line->HasSwitch("h") ||
+      command_line->HasSwitch("?") || !command_line->GetArgs().empty()) {
     fprintf(stderr,
-            "Usage: %s --name=<hostname> [--code=<auth-code>] [--pin=<PIN>] "
+            "Usage: %s [--name=<hostname>] [--code=<auth-code>] [--pin=<PIN>] "
             "[--redirect-url=<redirectURL>]\n",
             argv[0]);
-    fprintf(stderr, "\nAuthorization URL for Production services:\n");
-    fprintf(stderr, "%s\n", GetAuthorizationCodeUri().c_str());
     return 1;
   }
 
+  if (host_name.empty()) {
+    fprintf(stdout, "Enter a name for this computer: ");
+    fflush(stdout);
+    host_name = ReadString(false);
+  }
+
   if (host_pin.empty()) {
     while (true) {
       fprintf(stdout, "Enter a PIN of at least six digits: ");
       fflush(stdout);
       host_pin = ReadString(true);
       if (!remoting::IsPinValid(host_pin)) {
         fprintf(stdout,
                 "Please use a PIN consisting of at least six digits.\n");
         fflush(stdout);
         continue;
@@ skipping 10 matching lines @@
       break;
     }
   } else {
     if (!remoting::IsPinValid(host_pin)) {
       fprintf(stderr, "Please use a PIN consisting of at least six digits.\n");
       return 1;
     }
   }
 
   if (auth_code.empty()) {
+    fprintf(stdout, "\nAuthorization URL for Production services:\n");
+    fprintf(stdout, "%s\n\n", GetAuthorizationCodeUri().c_str());
     fprintf(stdout, "Enter an authorization code: ");
     fflush(stdout);
     auth_code = ReadString(true);
   }
 
   // Provide message loops and threads for the URLRequestContextGetter.
   base::MessageLoop message_loop;
   g_message_loop = &message_loop;
   base::Thread::Options io_thread_options(base::MessageLoop::TYPE_IO, 0);
   base::Thread io_thread("IO thread");
@@ skipping 28 matching lines @@
   // IO thread.
   host_starter.reset();
   url_request_context_getter = nullptr;
 
   io_thread.Stop();
 
   return g_started ? 0 : 1;
 }
 
 }  // namespace remoting