Add error messages in Daemon::Kill().

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 237 matching lines @@
   // Restore the previous signal action for SIGCHLD.
   if (sigaction(SIGCHLD, &old_action, NULL) < 0) {
     PError("sigaction");
     failed = true;
   }
   return !failed;
 }
 
 bool Daemon::Kill() {
   pid_t daemon_pid = Socket::GetUnixDomainSocketProcessOwner(identifier_);
-  if (daemon_pid < 0)
-    return true;  // No daemon running.
+  if (daemon_pid < 0) {
+    LOG(ERROR) << "No forwarder daemon seems to be running";
+    return true;
+  }
   if (kill(daemon_pid, SIGTERM) < 0) {
-    if (errno == ESRCH /* invalid PID */)
+    if (errno == ESRCH /* invalid PID */) {
       // The daemon exited for some reason (e.g. kill by a process other than
       // us) right before the call to kill() above.
+      LOG(ERROR) << "Could not kill daemon with PID " << daemon_pid;
       return true;
+    }
     PError("kill");
     return false;
   }
   for (int i = 0; i < kNumTries; ++i) {
     const pid_t previous_pid = daemon_pid;
     daemon_pid = Socket::GetUnixDomainSocketProcessOwner(identifier_);
     if (daemon_pid < 0)
       return true;
     // Since we are polling we might not see the 'daemon exited' event if
     // another daemon was spawned during our idle period.
     if (daemon_pid != previous_pid) {
       LOG(WARNING) << "Daemon (pid=" << previous_pid
                    << ") was successfully killed but a new daemon (pid="
                    << daemon_pid << ") seems to be running now.";
       return true;
     }
     usleep(kIdleTimeMSec * 1000);
   }
   LOG(ERROR) << "Timed out while killing daemon. "
                 "It might still be tearing down.";
   return false;
 }
 
 }  // namespace forwarder2