bluetooth: Detect and fix incorrect thread usage of BluetoothDispatcherHost.

content/browser/bluetooth/bluetooth_dispatcher_host.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.
 
 // NETWORK_ERROR Note:
 // When a device can't be found in the BluetoothAdapter, that generally
 // indicates that it's gone out of range. We reject with a NetworkError in that
 // case.
 // https://webbluetoothchrome.github.io/web-bluetooth/#dom-bluetoothdevice-connectgatt
 
@@ skipping 153 matching lines @@
           // TODO(jyasskin): Add a way for tests to control the dialog
           // directly, and change this to a reasonable discovery timeout.
           base::TimeDelta::FromSecondsD(current_delay_time_),
           base::Bind(&BluetoothDispatcherHost::StopDeviceDiscovery,
                      // base::Timer guarantees it won't call back after its
                      // destructor starts.
                      base::Unretained(this)),
           /*is_repeating=*/false),
       weak_ptr_factory_(this) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  // Bind all future weak pointers to the UI thread.
+  weak_ptr_on_ui_thread_ = weak_ptr_factory_.GetWeakPtr();
+  weak_ptr_on_ui_thread_.get();
+
   if (BluetoothAdapterFactory::IsBluetoothAdapterAvailable())
     BluetoothAdapterFactory::GetAdapter(
         base::Bind(&BluetoothDispatcherHost::set_adapter,
                    weak_ptr_factory_.GetWeakPtr()));

[qinmin, 2015/10/05 18:38:54]

use weak_ptr_on_ui_thread_ and everywhere else in this file?

[scheib, 2015/10/05 21:01:33]

Done. [Obviously] I didn't think of that, but it is much clearer that way,
thanks.

 }
 
 void BluetoothDispatcherHost::OnDestruct() const {
   // See class comment: UI Thread Note.
   BrowserThread::DeleteOnUIThread::Destruct(this);
 }
 
 void BluetoothDispatcherHost::OverrideThreadForMessage(
     const IPC::Message& message,
     content::BrowserThread::ID* thread) {
@@ skipping 746 matching lines @@
 
 void BluetoothDispatcherHost::ShowBluetoothPairingLink() {
   NOTIMPLEMENTED();
 }
 
 void BluetoothDispatcherHost::ShowBluetoothAdapterOffLink() {
   NOTIMPLEMENTED();
 }
 
 }  // namespace content