Revert of Revert of [Easy Unlock] Port the BluetoothConnectionFinder class to native code.

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/message_loop/message_loop.h"
 #include "base/numerics/safe_conversions.h"
 #include "components/proximity_auth/bluetooth_util.h"
@@ skipping 102 matching lines @@
                    base::Bind(&BluetoothConnection::OnReceiveError, weak_this));
 }
 
 void BluetoothConnection::OnAdapterInitialized(
     scoped_refptr<device::BluetoothAdapter> adapter) {
   const std::string address = remote_device().bluetooth_address;
   device::BluetoothDevice* bluetooth_device = adapter->GetDevice(address);
   if (!bluetooth_device) {
     VLOG(1) << "[BC] Device with address " << address
             << " is not known to the system Bluetooth daemon.";
+    // TOOD(isherman): Optimistically attempt to seek the device and connect
+    // anyway, as was previously implemented in BluetoothConnectionFinder.
     Disconnect();
     return;
   }
 
   adapter_ = adapter;
   adapter_->AddObserver(this);
 
   base::WeakPtr<BluetoothConnection> weak_this = weak_ptr_factory_.GetWeakPtr();
   ConnectToService(
       bluetooth_device,
@@ skipping 59 matching lines @@
 
   // 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::MessageLoop::current()->PostTask(
       FROM_HERE,
       base::Bind(&BluetoothConnection::StartReceive,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 }  // namespace proximity_auth