Motown: media_test minor fixes and cleanup.

examples/media_test/media_test.h

 // Copyright 2015 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 EXAMPLES_MEDIA_TEST_MEDIA_TEST_H_
 #define EXAMPLES_MEDIA_TEST_MEDIA_TEST_H_
 
 #include "base/macros.h"
 #include "mojo/public/cpp/application/application_impl.h"
 #include "mojo/services/media/common/cpp/linear_transform.h"
 #include "mojo/services/media/common/interfaces/rate_control.mojom.h"
 #include "mojo/services/media/control/interfaces/media_factory.mojom.h"
 #include "mojo/services/media/control/interfaces/media_player.mojom.h"
 
 namespace mojo {
 namespace media {
 namespace examples {
 
 // Model for media test application.
 class MediaTest {
  public:
   using UpdateCallback = std::function<void()>;
 
   static std::unique_ptr<MediaTest> Create(mojo::ApplicationImpl* app,
                                            const std::string& input_file_name);
 
   ~MediaTest();
 
   // Registers a callback signalling that the app should update its view.
-  void RegisterUpdateCallback(const UpdateCallback& callback);
+  void RegisterUpdateCallback(const UpdateCallback& callback) {
+    update_callback_ = callback;
+  }
 
   // Starts playback.
-  void Play();
+  void Play() { media_player_->Play(); }
 
   // Pauses playback.
-  void Pause();
+  void Pause() { media_player_->Pause(); }
 
   // Seeks to the position indicated in nanoseconds from the start of the media.
-  void Seek(int64_t position_ns);
+  void Seek(int64_t position_ns) { media_player_->Seek(position_ns); }
+
+  // Returns the previous state of the player.
+  MediaState previous_state() const { return previous_state_; }
 
   // Returns the current state of the player.
-  MediaState state() const;
+  MediaState state() const { return state_; }
 
   // Returns the current presentation time in nanoseconds.
   int64_t position_ns() const;
 
   // Returns the current media metadata, if there is any.
   const MediaMetadataPtr& metadata() const;
 
  private:
   MediaTest(mojo::ApplicationImpl* app, const std::string& input_file_name);
 
   // Handles a status update from the player. When called with the default
   // argument values, initiates status updates.
   void HandleStatusUpdates(uint64_t version = MediaPlayer::kInitialStatus,
                            MediaPlayerStatusPtr status = nullptr);
 
   MediaPlayerPtr media_player_;
-  MediaState state_;
+  MediaState previous_state_ = MediaState::UNPREPARED;
+  MediaState state_ = MediaState::UNPREPARED;
   LinearTransform transform_ = LinearTransform(0, 0, 1, 0);
   MediaMetadataPtr metadata_;
   UpdateCallback update_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaTest);
 };
 
 }  // namespace examples
 }  // namespace media
 }  // namespace mojo
 
 #endif  // EXAMPLES_MEDIA_TEST_MEDIA_TEST_H_