[DevTools] Port forwarding doesn't keep USB connection

chrome/browser/devtools/device/devtools_android_bridge.cc

Index: chrome/browser/devtools/device/devtools_android_bridge.cc
diff --git a/chrome/browser/devtools/device/devtools_android_bridge.cc b/chrome/browser/devtools/device/devtools_android_bridge.cc
index 97d6834ea78a13430774da404b8228dd4dbaf1ff..dbc2a651d9c8af11aeb20cadb946399dc35040fb 100644
--- a/chrome/browser/devtools/device/devtools_android_bridge.cc
+++ b/chrome/browser/devtools/device/devtools_android_bridge.cc
@@ -309,6 +309,7 @@ class DevToolsAndroidBridge::AgentHostDelegate
   bool socket_opened_;
   bool is_web_view_;
   std::vector<std::string> pending_messages_;
+  scoped_refptr<AndroidDeviceManager::Device> device_;
   scoped_ptr<AndroidDeviceManager::AndroidWebSocket> web_socket_;
   content::DevToolsAgentHost* agent_host_;
   content::DevToolsExternalAgentProxy* proxy_;
@@ -362,12 +363,21 @@ void DevToolsAndroidBridge::AgentHostDelegate::Attach(
   proxy_ = proxy;
   content::RecordAction(base::UserMetricsAction(is_web_view_ ?
       "DevTools_InspectAndroidWebView" : "DevTools_InspectAndroidPage"));
+
+  DeviceMap& device_map(bridge_->device_map_);
+  DeviceMap::iterator it = device_map.find(browser_id_.first);
+  if (it == device_map.end())
+    return;
+
+  // Retain the device so it's not released until AgentHost is detached.
+  device_ = it->second;
   web_socket_.reset(
-      bridge_->CreateWebSocket(browser_id_, debug_url_, this));
+      device_->CreateWebSocket(browser_id_.second, debug_url_, this));
 }
 
 void DevToolsAndroidBridge::AgentHostDelegate::Detach() {
   web_socket_.reset();
+  device_ = nullptr;
 }
 
 void DevToolsAndroidBridge::AgentHostDelegate::SendMessageToBackend(
@@ -633,18 +643,6 @@ DevToolsAndroidBridge::GetBrowserAgentHost(
       browser->IsWebView());
 }
 
-AndroidDeviceManager::AndroidWebSocket*
-DevToolsAndroidBridge::CreateWebSocket(
-    const BrowserId& browser_id,
-    const std::string& url,
-    AndroidDeviceManager::AndroidWebSocket::Delegate* delegate) {
-  DeviceMap::iterator it = device_map_.find(browser_id.first);
-  if (it == device_map_.end())
-    return NULL;
-
-  return it->second->CreateWebSocket(browser_id.second, url, delegate);
-}
-
 void DevToolsAndroidBridge::RespondToOpenOnUIThread(
     scoped_refptr<RemoteBrowser> browser,
     const RemotePageCallback& callback,