DevTools: retain DTAH in all the targets to match their life time.

chrome/browser/devtools/device/devtools_device_discovery.cc

 // Copyright 2014 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 "chrome/browser/devtools/device/devtools_device_discovery.h"
 
 #include "base/bind.h"
 #include "base/json/json_reader.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/user_metrics.h"
@@ skipping 494 matching lines @@
 DevToolsDeviceDiscovery::RemotePage::~RemotePage() {
 }
 
 scoped_refptr<content::DevToolsAgentHost>
 DevToolsDeviceDiscovery::RemotePage::CreateTarget() {
   std::string local_id = BuildUniqueTargetId(device_->serial(),
                                              browser_id_,
                                              dict_.get());
   std::string target_path = GetTargetPath(dict_.get());
   std::string type = GetStringProperty(dict_.get(), "type");
-
-  return AgentHostDelegate::GetOrCreateAgentHost(
+  agent_host_ = AgentHostDelegate::GetOrCreateAgentHost(
       device_, browser_id_, local_id, target_path, type, dict_.get());
+  return agent_host_;
 }
 
 // DevToolsDeviceDiscovery::RemoteBrowser -------------------------------------
 
 DevToolsDeviceDiscovery::RemoteBrowser::RemoteBrowser(
     const std::string& serial,
     const AndroidDeviceManager::BrowserInfo& browser_info)
     : serial_(serial),
       browser_id_(browser_info.socket_name),
       display_name_(browser_info.display_name),
@@ skipping 89 matching lines @@
 }
 
 void DevToolsDeviceDiscovery::ReceivedDeviceList(
     const CompleteDevices& complete_devices) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   task_scheduler_.Run(base::Bind(&DevToolsDeviceDiscovery::RequestDeviceList,
                                  weak_factory_.GetWeakPtr()));
   // |callback_| should be run last as it may destroy |this|.
   callback_.Run(complete_devices);
 }