Resubmit "Start chromoting host in the service process though a method call"

remoting/host/heartbeat_sender.cc

 // Copyright (c) 2010 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/heartbeat_sender.h"
 
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/string_number_conversions.h"
 #include "base/time.h"
@@ skipping 47 matching lines @@
   return true;
 }
 
 void HeartbeatSender::Start() {
   if (MessageLoop::current() != jingle_client_->message_loop()) {
     jingle_client_->message_loop()->PostTask(
         FROM_HERE, NewRunnableMethod(this, &HeartbeatSender::Start));
     return;
   }
 
-  DCHECK(state_ == INITIALIZED);
+  DCHECK_EQ(INITIALIZED, state_);
   state_ = STARTED;
 
   request_.reset(jingle_client_->CreateIqRequest());
   request_->set_callback(NewCallback(this, &HeartbeatSender::ProcessResponse));
 
   jingle_client_->message_loop()->PostTask(
       FROM_HERE, NewRunnableMethod(this, &HeartbeatSender::DoSendStanza));
 }
 
 void HeartbeatSender::Stop() {
   if (MessageLoop::current() != jingle_client_->message_loop()) {
     jingle_client_->message_loop()->PostTask(
         FROM_HERE, NewRunnableMethod(this, &HeartbeatSender::Stop));
     return;
   }
 
-  DCHECK(state_ == STARTED);
+  // We may call Stop() even if we have not started.
+  if (state_ != STARTED)
+    return;
   state_ = STOPPED;
   request_.reset(NULL);
 }
 
 void HeartbeatSender::DoSendStanza() {
   if (state_ == STARTED) {
     // |jingle_client_| may be already destroyed if |state_| is set to
     // |STOPPED|, so don't touch it here unless we are in |STARTED| state.
     DCHECK(MessageLoop::current() == jingle_client_->message_loop());
 
@@ skipping 34 matching lines @@
       buzz::QName(kChromotingXmlNamespace, kSignatureTimeAttr), time_str);
 
   std::string message = jingle_client_->GetFullJid() + ' ' + time_str;
   std::string signature(key_pair_.GetSignature(message));
   signature_tag->AddText(signature);
 
   return signature_tag;
 }
 
 }  // namespace remoting