Fix BluetoothConnection to disconnect when the underlying device disconnects.

components/proximity_auth/bluetooth_connection.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 "components/proximity_auth/bluetooth_connection.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/single_thread_task_runner.h"
@@ skipping 70 matching lines @@
 
   // Send it.
   pending_message_ = message.Pass();
   base::WeakPtr<BluetoothConnection> weak_this = weak_ptr_factory_.GetWeakPtr();
   socket_->Send(buffer,
                 message_length,
                 base::Bind(&BluetoothConnection::OnSend, weak_this),
                 base::Bind(&BluetoothConnection::OnSendError, weak_this));
 }
 
+void BluetoothConnection::DeviceChanged(device::BluetoothAdapter* adapter,
+                                        device::BluetoothDevice* device) {
+  DCHECK_EQ(adapter, adapter_.get());
+  if (device->GetAddress() == remote_device().bluetooth_address &&
+      status() != DISCONNECTED && !device->IsConnected()) {
+    PA_LOG(INFO) << "Device disconnected...";
+    Disconnect();
+  }
+}
+
 void BluetoothConnection::DeviceRemoved(device::BluetoothAdapter* adapter,
                                         device::BluetoothDevice* device) {
   DCHECK_EQ(adapter, adapter_.get());
   if (device->GetAddress() != remote_device().bluetooth_address)
     return;
 
   DCHECK_NE(status(), DISCONNECTED);
   PA_LOG(INFO) << "Device disconnected...";
-  Disconnect();
+  if (status() != DISCONNECTED)
+    Disconnect();
 }
 
 void BluetoothConnection::StartReceive() {
   base::WeakPtr<BluetoothConnection> weak_this = weak_ptr_factory_.GetWeakPtr();
   socket_->Receive(kReceiveBufferSizeBytes,
                    base::Bind(&BluetoothConnection::OnReceive, weak_this),
                    base::Bind(&BluetoothConnection::OnReceiveError, weak_this));
 }
 
 void BluetoothConnection::OnAdapterInitialized(
@@ skipping 74 matching lines @@
   PA_LOG(WARNING) << "Error receiving bytes: " << error_message;
 
   // Post a task to delay the read until the socket is available, as
   // calling StartReceive at this point would error with ERR_IO_PENDING.
   base::ThreadTaskRunnerHandle::Get()->PostTask(
       FROM_HERE, base::Bind(&BluetoothConnection::StartReceive,
                             weak_ptr_factory_.GetWeakPtr()));
 }
 
 }  // namespace proximity_auth