Add support for the audio-output-device switching IPC mechanism to the renderer lower layers (media::AudioOutputDevice, content::AudioMessageFilter and related classes).

The idea is to provide support for the Audio Output Devices API (http://w3c.github.io/mediacapture-output/)

BUG=438023

Committed: https://crrev.com/8c7fc2c8746c9cb294a5906572f23fbfc34726b3
Cr-Commit-Position: refs/heads/master@{#334451}

Review URL: https://codereview.chromium.org/1184473002

Cr-Commit-Position: refs/heads/master@{#334520}

11 files changed, 173 insertions, 2 deletions

diff --git a/media/audio/BUILD.gn b/media/audio/BUILD.gn
index 11d3d76..ccc6f69 100644
--- a/media/audio/BUILD.gn
+++ b/media/audio/BUILD.gn
@@ -290,6 +290,7 @@ source_set("unittests") {
     "//media/base:test_support",
     "//testing/gmock",
     "//testing/gtest",
+    "//url",
   ]
 
   configs += [
diff --git a/media/audio/audio_output_device.cc b/media/audio/audio_output_device.cc
index d55d100..3213400 100644
--- a/media/audio/audio_output_device.cc
+++ b/media/audio/audio_output_device.cc
@@ -4,6 +4,9 @@
 
 #include "media/audio/audio_output_device.h"
 
+#include <string>
+
+#include "base/callback_helpers.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
@@ -45,7 +48,8 @@ AudioOutputDevice::AudioOutputDevice(
       state_(IDLE),
       play_on_start_(true),
       session_id_(-1),
-      stopping_hack_(false) {
+      stopping_hack_(false),
+      current_switch_request_id_(0) {
   CHECK(ipc_);
 
   // The correctness of the code depends on the relative values assigned in the
@@ -75,6 +79,14 @@ AudioOutputDevice::~AudioOutputDevice() {
   // The current design requires that the user calls Stop() before deleting
   // this class.
   DCHECK(audio_thread_.IsStopped());
+
+  // The following makes it possible for |current_switch_callback_| to release
+  // its bound parameters in the correct thread instead of implicitly releasing
+  // them in the thread where this destructor runs.
+  if (!current_switch_callback_.is_null()) {
+    base::ResetAndReturn(&current_switch_callback_).Run(
+        SWITCH_OUTPUT_DEVICE_RESULT_ERROR_OBSOLETE);
+  }
 }
 
 void AudioOutputDevice::Start() {
@@ -117,6 +129,16 @@ bool AudioOutputDevice::SetVolume(double volume) {
   return true;
 }
 
+void AudioOutputDevice::SwitchOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const SwitchOutputDeviceCB& callback) {
+  DVLOG(1) << __FUNCTION__ << "(" << device_id << ")";
+  task_runner()->PostTask(
+      FROM_HERE, base::Bind(&AudioOutputDevice::SwitchOutputDeviceOnIOThread,
+                            this, device_id, security_origin, callback));
+}
+
 void AudioOutputDevice::CreateStreamOnIOThread(const AudioParameters& params) {
   DCHECK(task_runner()->BelongsToCurrentThread());
   if (state_ == IDLE) {
@@ -179,6 +201,21 @@ void AudioOutputDevice::SetVolumeOnIOThread(double volume) {
     ipc_->SetVolume(volume);
 }
 
+void AudioOutputDevice::SwitchOutputDeviceOnIOThread(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const SwitchOutputDeviceCB& callback) {
+  DCHECK(task_runner()->BelongsToCurrentThread());
+  DVLOG(1) << __FUNCTION__ << "(" << device_id << "," << security_origin << ")";
+  if (state_ >= CREATING_STREAM) {
+    SetCurrentSwitchRequest(callback);
+    ipc_->SwitchOutputDevice(device_id, security_origin,
+                             current_switch_request_id_);
+  } else {
+    callback.Run(SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED);
+  }
+}
+
 void AudioOutputDevice::OnStateChanged(AudioOutputIPCDelegateState state) {
   DCHECK(task_runner()->BelongsToCurrentThread());
 
@@ -254,6 +291,32 @@ void AudioOutputDevice::OnStreamCreated(
     PlayOnIOThread();
 }
 
+void AudioOutputDevice::SetCurrentSwitchRequest(
+    const SwitchOutputDeviceCB& callback) {
+  DCHECK(task_runner()->BelongsToCurrentThread());
+  DVLOG(1) << __FUNCTION__;
+  // If there is a previous unresolved request, resolve it as obsolete
+  if (!current_switch_callback_.is_null()) {
+    base::ResetAndReturn(&current_switch_callback_).Run(
+        SWITCH_OUTPUT_DEVICE_RESULT_ERROR_OBSOLETE);
+  }
+  current_switch_callback_ = callback;
+  current_switch_request_id_++;
+}
+
+void AudioOutputDevice::OnOutputDeviceSwitched(
+    int request_id,
+    SwitchOutputDeviceResult result) {
+  DCHECK(task_runner()->BelongsToCurrentThread());
+  DCHECK(request_id <= current_switch_request_id_);
+  DVLOG(1) << __FUNCTION__
+           << "(" << request_id << ", " << result << ")";
+  if (request_id != current_switch_request_id_) {
+    return;
+  }
+  base::ResetAndReturn(&current_switch_callback_).Run(result);
+}
+
 void AudioOutputDevice::OnIPCClosed() {
   DCHECK(task_runner()->BelongsToCurrentThread());
   state_ = IPC_CLOSED;
diff --git a/media/audio/audio_output_device.h b/media/audio/audio_output_device.h
index 6255c71..dc28352 100644
--- a/media/audio/audio_output_device.h
+++ b/media/audio/audio_output_device.h
@@ -58,6 +58,8 @@
 #ifndef MEDIA_AUDIO_AUDIO_OUTPUT_DEVICE_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_DEVICE_H_
 
+#include <string>
+
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
@@ -95,6 +97,9 @@ class MEDIA_EXPORT AudioOutputDevice
   void Play() override;
   void Pause() override;
   bool SetVolume(double volume) override;
+  void SwitchOutputDevice(const std::string& device_id,
+                          const GURL& security_origin,
+                          const SwitchOutputDeviceCB& callback) override;
 
   // Methods called on IO thread ----------------------------------------------
   // AudioOutputIPCDelegate methods.
@@ -102,6 +107,8 @@ class MEDIA_EXPORT AudioOutputDevice
   void OnStreamCreated(base::SharedMemoryHandle handle,
                        base::SyncSocket::Handle socket_handle,
                        int length) override;
+  void OnOutputDeviceSwitched(int request_id,
+                              SwitchOutputDeviceResult result) override;
   void OnIPCClosed() override;
 
  protected:
@@ -129,11 +136,16 @@ class MEDIA_EXPORT AudioOutputDevice
   void PauseOnIOThread();
   void ShutDownOnIOThread();
   void SetVolumeOnIOThread(double volume);
+  void SwitchOutputDeviceOnIOThread(const std::string& device_id,
+                                    const GURL& security_origin,
+                                    const SwitchOutputDeviceCB& callback);
 
   // base::MessageLoop::DestructionObserver implementation for the IO loop.
   // If the IO loop dies before we do, we shut down the audio thread from here.
   void WillDestroyCurrentMessageLoop() override;
 
+  void SetCurrentSwitchRequest(const SwitchOutputDeviceCB& callback);
+
   AudioParameters audio_parameters_;
 
   RenderCallback* callback_;
@@ -171,6 +183,9 @@ class MEDIA_EXPORT AudioOutputDevice
   // the callback via Start(). See http://crbug.com/151051 for details.
   bool stopping_hack_;
 
+  int current_switch_request_id_;
+  SwitchOutputDeviceCB current_switch_callback_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioOutputDevice);
 };
 
diff --git a/media/audio/audio_output_device_unittest.cc b/media/audio/audio_output_device_unittest.cc
index d803483..3b3ee51 100644
--- a/media/audio/audio_output_device_unittest.cc
+++ b/media/audio/audio_output_device_unittest.cc
@@ -5,11 +5,15 @@
 #include <vector>
 
 #include "base/at_exit.h"
+#include "base/bind_helpers.h"
+#include "base/callback.h"
 #include "base/memory/shared_memory.h"
 #include "base/message_loop/message_loop.h"
 #include "base/process/process_handle.h"
 #include "base/sync_socket.h"
+#include "base/task_runner.h"
 #include "base/test/test_timeouts.h"
+#include "base/thread_task_runner_handle.h"
 #include "media/audio/audio_output_device.h"
 #include "media/audio/sample_rates.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -52,6 +56,15 @@ class MockAudioOutputIPC : public AudioOutputIPC {
   MOCK_METHOD0(PauseStream, void());
   MOCK_METHOD0(CloseStream, void());
   MOCK_METHOD1(SetVolume, void(double volume));
+  MOCK_METHOD3(SwitchOutputDevice,
+               void(const std::string& device_id,
+                    const GURL& security_origin,
+                    int request_id));
+};
+
+class MockSwitchOutputDeviceCallback {
+ public:
+  MOCK_METHOD1(Callback, void(media::SwitchOutputDeviceResult result));
 };
 
 ACTION_P2(SendPendingBytes, socket, pending_bytes) {
@@ -78,6 +91,7 @@ class AudioOutputDeviceTest
   void ExpectRenderCallback();
   void WaitUntilRenderCallback();
   void StopAudioDevice();
+  void SwitchOutputDevice();
 
  protected:
   // Used to clean up TLS pointers that the test(s) will initialize.
@@ -88,9 +102,11 @@ class AudioOutputDeviceTest
   StrictMock<MockRenderCallback> callback_;
   MockAudioOutputIPC* audio_output_ipc_;  // owned by audio_device_
   scoped_refptr<AudioOutputDevice> audio_device_;
+  MockSwitchOutputDeviceCallback switch_output_device_callback_;
 
  private:
   int CalculateMemorySize();
+  void SwitchOutputDeviceCallback(SwitchOutputDeviceResult result);
 
   SharedMemory shared_memory_;
   CancelableSyncSocket browser_socket_;
@@ -196,6 +212,28 @@ void AudioOutputDeviceTest::StopAudioDevice() {
   io_loop_.RunUntilIdle();
 }
 
+void AudioOutputDeviceTest::SwitchOutputDevice() {
+  const GURL security_origin("http://localhost");
+  const std::string device_id;
+  const int request_id = 1;
+
+  // Switch the output device and check that the IPC message is sent
+  EXPECT_CALL(*audio_output_ipc_,
+              SwitchOutputDevice(device_id, security_origin, request_id));
+  audio_device_->SwitchOutputDevice(
+      device_id, security_origin,
+      base::Bind(&MockSwitchOutputDeviceCallback::Callback,
+                 base::Unretained(&switch_output_device_callback_)));
+  io_loop_.RunUntilIdle();
+
+  // Simulate the reception of a successful response from the browser
+  EXPECT_CALL(switch_output_device_callback_,
+              Callback(SWITCH_OUTPUT_DEVICE_RESULT_SUCCESS));
+  audio_device_->OnOutputDeviceSwitched(request_id,
+                                        SWITCH_OUTPUT_DEVICE_RESULT_SUCCESS);
+  io_loop_.RunUntilIdle();
+}
+
 TEST_P(AudioOutputDeviceTest, Initialize) {
   // Tests that the object can be constructed, initialized and destructed
   // without having ever been started/stopped.
@@ -239,6 +277,13 @@ TEST_P(AudioOutputDeviceTest, CreateStream) {
   StopAudioDevice();
 }
 
+// Switch the output device
+TEST_P(AudioOutputDeviceTest, SwitchOutputDevice) {
+  StartAudioDevice();
+  SwitchOutputDevice();
+  StopAudioDevice();
+}
+
 INSTANTIATE_TEST_CASE_P(Render, AudioOutputDeviceTest, Values(false));
 
 }  // namespace media.
diff --git a/media/audio/audio_output_ipc.h b/media/audio/audio_output_ipc.h
index 9af1df4..2115508 100644
--- a/media/audio/audio_output_ipc.h
+++ b/media/audio/audio_output_ipc.h
@@ -57,6 +57,10 @@ class MEDIA_EXPORT AudioOutputIPCDelegate {
                                base::SyncSocket::Handle socket_handle,
                                int length) = 0;
 
+  // Called when an attempt to switch the output device has been completed
+  virtual void OnOutputDeviceSwitched(int request_id,
+                                      SwitchOutputDeviceResult result) = 0;
+
   // Called when the AudioOutputIPC object is going away and/or when the IPC
   // channel has been closed and no more ipc requests can be made.
   // Implementations should delete their owned AudioOutputIPC instance
@@ -99,6 +103,11 @@ class MEDIA_EXPORT AudioOutputIPC {
 
   // Sets the volume of the audio stream.
   virtual void SetVolume(double volume) = 0;
+
+  // Switches the output device of the audio stream.
+  virtual void SwitchOutputDevice(const std::string& device_id,
+                                  const GURL& security_origin,
+                                  int request_id) = 0;
 };
 
 }  // namespace media
diff --git a/media/audio/audio_output_stream_sink.cc b/media/audio/audio_output_stream_sink.cc
index e233e99..e290e0f 100644
--- a/media/audio/audio_output_stream_sink.cc
+++ b/media/audio/audio_output_stream_sink.cc
@@ -57,7 +57,14 @@ bool AudioOutputStreamSink::SetVolume(double volume) {
   audio_task_runner_->PostTask(
       FROM_HERE, base::Bind(&AudioOutputStreamSink::DoSetVolume, this, volume));
   return true;
-};
+}
+
+void AudioOutputStreamSink::SwitchOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const SwitchOutputDeviceCB& callback) {
+  callback.Run(SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED);
+}
 
 int AudioOutputStreamSink::OnMoreData(AudioBus* dest,
                                       uint32 total_bytes_delay) {
diff --git a/media/audio/audio_output_stream_sink.h b/media/audio/audio_output_stream_sink.h
index c6f04a7..9d99fb7 100644
--- a/media/audio/audio_output_stream_sink.h
+++ b/media/audio/audio_output_stream_sink.h
@@ -5,6 +5,8 @@
 #ifndef MEDIA_AUDIO_AUDIO_OUTPUT_STREAM_SINK_H_
 #define MEDIA_AUDIO_AUDIO_OUTPUT_STREAM_SINK_H_
 
+#include <string>
+
 #include "base/compiler_specific.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
@@ -34,6 +36,9 @@ class MEDIA_EXPORT AudioOutputStreamSink
   void Pause() override;
   void Play() override;
   bool SetVolume(double volume) override;
+  void SwitchOutputDevice(const std::string& device_id,
+                          const GURL& security_origin,
+                          const SwitchOutputDeviceCB& callback) override;
 
   // AudioSourceCallback implementation.
   int OnMoreData(AudioBus* dest, uint32 total_bytes_delay) override;
diff --git a/media/audio/clockless_audio_sink.cc b/media/audio/clockless_audio_sink.cc
index 44e9adb..60c839c 100644
--- a/media/audio/clockless_audio_sink.cc
+++ b/media/audio/clockless_audio_sink.cc
@@ -4,6 +4,9 @@
 
 #include "media/audio/clockless_audio_sink.h"
 
+#include "base/bind.h"
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
 #include "base/threading/simple_thread.h"
 
 namespace media {
@@ -105,4 +108,11 @@ bool ClocklessAudioSink::SetVolume(double volume) {
   return volume == 0.0;
 }
 
+void ClocklessAudioSink::SwitchOutputDevice(
+    const std::string& device_id,
+    const GURL& security_origin,
+    const SwitchOutputDeviceCB& callback) {
+  callback.Run(SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED);
+}
+
 }  // namespace media
diff --git a/media/audio/clockless_audio_sink.h b/media/audio/clockless_audio_sink.h
index 075c55a..2251b00 100644
--- a/media/audio/clockless_audio_sink.h
+++ b/media/audio/clockless_audio_sink.h
@@ -5,6 +5,8 @@
 #ifndef MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_
 #define MEDIA_AUDIO_CLOCKLESS_AUDIO_SINK_H_
 
+#include <string>
+
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "media/base/audio_renderer_sink.h"
@@ -32,6 +34,9 @@ class MEDIA_EXPORT ClocklessAudioSink
   void Pause() override;
   void Play() override;
   bool SetVolume(double volume) override;
+  void SwitchOutputDevice(const std::string& device_id,
+                          const GURL& security_origin,
+                          const SwitchOutputDeviceCB& callback) override;
 
   // Returns the time taken to consume all the audio.
   base::TimeDelta render_time() { return playback_time_; }
diff --git a/media/audio/null_audio_sink.cc b/media/audio/null_audio_sink.cc
index e737c43..fc5e900 100644
--- a/media/audio/null_audio_sink.cc
+++ b/media/audio/null_audio_sink.cc
@@ -5,6 +5,7 @@
 #include "media/audio/null_audio_sink.h"
 
 #include "base/bind.h"
+#include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "media/audio/fake_audio_worker.h"
 #include "media/base/audio_hash.h"
@@ -70,6 +71,13 @@ bool NullAudioSink::SetVolume(double volume) {
   return volume == 0.0;
 }
 
+void NullAudioSink::SwitchOutputDevice(const std::string& device_id,
+                                       const GURL& security_origin,
+                                       const SwitchOutputDeviceCB& callback) {
+  DCHECK(task_runner_->BelongsToCurrentThread());
+  callback.Run(SWITCH_OUTPUT_DEVICE_RESULT_ERROR_NOT_SUPPORTED);
+}
+
 void NullAudioSink::CallRender() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
diff --git a/media/audio/null_audio_sink.h b/media/audio/null_audio_sink.h
index 1abdb99..d8d5f04 100644
--- a/media/audio/null_audio_sink.h
+++ b/media/audio/null_audio_sink.h
@@ -32,6 +32,9 @@ class MEDIA_EXPORT NullAudioSink
   void Pause() override;
   void Play() override;
   bool SetVolume(double volume) override;
+  void SwitchOutputDevice(const std::string& device_id,
+                          const GURL& security_origin,
+                          const SwitchOutputDeviceCB& callback) override;
 
   // Enables audio frame hashing.  Must be called prior to Initialize().
   void StartAudioHashForTesting();