Reland "Add --serial-id option to host_forwarder."

tools/android/forwarder2/daemon.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 "tools/android/forwarder2/daemon.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <sys/file.h>
@@ skipping 123 matching lines @@
   for (int i = 0; i < tries_count; ++i) {
     scoped_ptr<Socket> socket(new Socket());
     if (!socket->ConnectUnix(socket_name)) {
       if (idle_time_msec)
         usleep(idle_time_msec * 1000);
       continue;
     }
     char buf[kBufferSize];
     DCHECK(expected_welcome_message.length() + 1 <= sizeof(buf));
     memset(buf, 0, sizeof(buf));
-    if (socket->Read(buf, sizeof(buf)) < 0) {
+    if (socket->Read(buf, expected_welcome_message.length() + 1) < 0) {
       perror("read");
       continue;
     }
     if (expected_welcome_message != buf) {
       LOG(ERROR) << "Unexpected message read from daemon: " << buf;
       break;
     }
     return socket.Pass();
   }
   return scoped_ptr<Socket>();
@@ skipping 125 matching lines @@
       return true;
     }
     usleep(kIdleTimeMSec * 1000);
   }
   LOG(ERROR) << "Timed out while killing daemon. "
                 "It might still be tearing down.";
   return false;
 }
 
 }  // namespace forwarder2