Implement finding BLE connections in chrome://proximity-auth.

components/proximity_auth/bluetooth_connection_finder.h

 // 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.
 
 #ifndef COMPONENTS_PROXIMITY_AUTH_BLUETOOTH_CONNECTION_FINDER_H
 #define COMPONENTS_PROXIMITY_AUTH_BLUETOOTH_CONNECTION_FINDER_H
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/time/time.h"
+#include "components/proximity_auth/bluetooth_util.h"
 #include "components/proximity_auth/connection_finder.h"
 #include "components/proximity_auth/connection_observer.h"
 #include "components/proximity_auth/remote_device.h"
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_uuid.h"
 
 namespace proximity_auth {
 
 class BluetoothConnection;
 
 // This ConnectionFinder implementation tries to find a Bluetooth connection to
 // the remote device by polling at a fixed interval.
 class BluetoothConnectionFinder : public ConnectionFinder,
                                   public ConnectionObserver,
                                   public device::BluetoothAdapter::Observer {
  public:
   BluetoothConnectionFinder(const RemoteDevice& remote_device,
                             const device::BluetoothUUID& uuid,
                             const base::TimeDelta& polling_interval);
   ~BluetoothConnectionFinder() override;
 
   // ConnectionFinder:
   void Find(const ConnectionCallback& connection_callback) override;
 
  protected:
   // Exposed for mocking out the connection in tests.
   virtual scoped_ptr<Connection> CreateConnection();
 
+  // Calls bluetooth_util::SeekDeviceByAddress. Exposed for testing, as this
+  // utility function is platform dependent.
+  virtual void SeekDeviceByAddress(
+      const std::string& bluetooth_address,
+      const base::Closure& callback,
+      const bluetooth_util::ErrorCallback& error_callback);
+
   // BluetoothAdapter::Observer:
   void AdapterPresentChanged(device::BluetoothAdapter* adapter,
                              bool present) override;
   void AdapterPoweredChanged(device::BluetoothAdapter* adapter,
                              bool powered) override;
 
  private:
   // Returns true iff the Bluetooth adapter is ready to make connections.
   bool IsReadyToPoll();
 
   // Attempts to connect to the |remote_device_| if the system is ready for
   // another iteration of polling.
   void PollIfReady();
 
-  // Wrapper around |PollIfReady()| that can be posted as a delayed task.
-  void DelayedPollIfReady();
+  // Posts a delayed task to call |PollIfReady|. |OnDelayedPoll()| will be
+  // called when the task fires.
+  void PostDelayedPoll();
+  void OnDelayedPoll();
+
+  // Callbacks for bluetooth_util::SeekDeviceByAddress().
+  void OnSeekedDeviceByAddress();
+  void OnSeekedDeviceByAddressError(const std::string& error_message);
 
   // Unregisters |this| instance as an observer from all objects that it might
   // have registered with.
   void UnregisterAsObserver();
 
   // Callback to be called when the Bluetooth adapter is initialized.
   void OnAdapterInitialized(scoped_refptr<device::BluetoothAdapter> adapter);
 
   // ConnectionObserver:
   void OnConnectionStatusChanged(Connection* connection,
                                  Connection::Status old_status,
                                  Connection::Status new_status) override;
 
+  // Used to invokes |connection_callback_| asynchronously, decoupling the

[sacomoto, 2015/08/10 19:40:28]

nit: s/invokes/invoke/

[Tim Song, 2015/08/10 22:17:55]

Done.

+  // callback invocation from the ConnectionObserver callstack.
+  void InvokeCallbackAsync();
+
   // The remote device to connect to.
   const RemoteDevice remote_device_;
 
   // The UUID of the service on the remote device.
   const device::BluetoothUUID uuid_;
 
   // The time to wait between polling attempts.
   const base::TimeDelta polling_interval_;
 
   // Records the time at which the finder began searching for connections.
@@ skipping 17 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(BluetoothConnectionFinder);
 };
 
 // TODO(isherman): Make sure to wire up the controller to listen for screen lock
 // state change events, and create or destroy the connection finder as
 // appropriate.
 
 }  // namespace proximity_auth
 
 #endif  // COMPONENTS_PROXIMITY_AUTH_BLUETOOTH_CONNECTION_FINDER_H