device/bluetooth: Add I/O watcher for audio data retrieval triggered by state change.

chromeos/dbus/fake_bluetooth_media_transport_client.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 CHROMEOS_DBUS_FAKE_BLUETOOTH_MEDIA_TRANSPORT_CLIENT_H_
 #define CHROMEOS_DBUS_FAKE_BLUETOOTH_MEDIA_TRANSPORT_CLIENT_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
+#include "base/files/file.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/dbus/bluetooth_media_transport_client.h"
 #include "dbus/object_path.h"
 
 namespace chromeos {
 
 class FakeBluetoothMediaEndpointServiceProvider;
 
@@ skipping 47 matching lines @@
   // otherwise.
   void SetValid(FakeBluetoothMediaEndpointServiceProvider* endpoint,
                 bool valid);
 
   // Set state/volume property to a certain value.
   void SetState(const dbus::ObjectPath& endpoint_path,
                 const std::string& state);
   void SetVolume(const dbus::ObjectPath& endpoint_path,
                  const uint16_t& volume);
 
-  // Gets the transport path associated with the given endpoint path.
+  // Writes bytes to the input file descriptor, |input_fd|, accosiated with a

[armansito, 2015/03/12 03:42:54]

nit: s/accosiated/associated. Try pronouncing your version, it sounds funny.

[Miao, 2015/03/12 22:33:31]

:P

+  // Transport object which is bound to |endpoint_path|.

[armansito, 2015/03/12 03:42:54]

nit: s/Transport/transport/. Lowercase, because you probably don't want to be
referring to "struct Transport" which is private to this class.

[Miao, 2015/03/12 22:33:31]

Done.

+  void WriteData(const dbus::ObjectPath& endpoint_path,
+                 const std::vector<char>& bytes);
+
+  // Retrieves the transport object path bound to |endpoint_path|.
   dbus::ObjectPath GetTransportPath(const dbus::ObjectPath& endpoint_path);
 
   // Gets the endpoint path associated with the given transport_path.
   dbus::ObjectPath GetEndpointPath(const dbus::ObjectPath& transport_path);
 
  private:
   // This class is used for simulating the scenario where each media endpoint
   // has a corresponding transport path and properties. Once an endpoint is
   // assigned with a transport path, an object of Transport is created.
-  class Transport {
-   public:
+  struct Transport {
     Transport(const dbus::ObjectPath& transport_path,
               Properties* transport_properties);
     ~Transport();
 
     // An unique transport path.
     dbus::ObjectPath path;
 
     // The property set bound with |path|.
     scoped_ptr<Properties> properties;
+
+    // File descriptor for simulating data available event. |input_fd|
+    // will be initialized when Acquire/TryAcquire is called.

[armansito, 2015/03/12 03:42:54]

I would also say here that this is the internal end of the socketpair that gets
created for simulation purposes.

[Miao, 2015/03/12 22:33:31]

Done.

+    scoped_ptr<base::File> input_fd;
   };
 
   // Property callback passed while a Properties structure is created.
   void OnPropertyChanged(const std::string& property_name);
 
+  // Retrieves the transport structure bound to |endpoint_path|
+  Transport* GetTransport(const dbus::ObjectPath& endpoint_path);
+
   // Map of endpoints with valid transport. Each pair is composed of an endpoint
   // path and a Transport structure containing a transport path and its
   // properties.
   std::map<dbus::ObjectPath, Transport*> endpoint_to_transport_map_;
 
   // Map of valid transports. Each pair is composed of a transport path as the
   // key and an endpoint path as the value. This map is used to get the
   // corresponding endpoint path when GetProperties() is called.
   std::map<dbus::ObjectPath, dbus::ObjectPath> transport_to_endpoint_map_;
 
-  // The path of the media transport object.
-  dbus::ObjectPath object_path_;
-
   ObserverList<BluetoothMediaTransportClient::Observer> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeBluetoothMediaTransportClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_FAKE_BLUETOOTH_MEDIA_TRANSPORT_CLIENT_H_