Move android audio device code into sdk/android

This CL adds a stand-alone Android AudioDeviceModule in the
sdk/android folder. It's forked from modules/audio_device/android/
and then simplified for the Android case. The stand-alone Android
ADM is available both in the native_api and also under a field trial
in the Java API.

Bug: webrtc:7452
Change-Id: If6e558026bd0ccb52f56d78ac833339a5789d300
Reviewed-on: https://webrtc-review.googlesource.com/60541
Commit-Queue: Magnus Jedvert <magjed@webrtc.org>
Reviewed-by: Magnus Jedvert <magjed@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#22517}

sdk/android/native_api/DEPS

@@ -0,0 +1,4 @@
+include_rules = [
+  "+modules/audio_device/include/audio_device.h",
+  "+system_wrappers/include",
+]

sdk/android/native_api/audio_device_module/audio_device_android.cc

@@ -0,0 +1,69 @@
+/*
+ *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "sdk/android/native_api/audio_device_module/audio_device_android.h"
+
+#include <stdlib.h>
+#include "rtc_base/logging.h"
+#include "rtc_base/refcount.h"
+#include "rtc_base/refcountedobject.h"
+#include "system_wrappers/include/metrics.h"
+
+#if defined(AUDIO_DEVICE_INCLUDE_ANDROID_AAUDIO)
+#include "sdk/android/src/jni/audio_device/aaudio_player.h"
+#include "sdk/android/src/jni/audio_device/aaudio_recorder.h"
+#endif
+#include "sdk/android/src/jni/audio_device/audio_device_template_android.h"
+#include "sdk/android/src/jni/audio_device/audio_manager.h"
+#include "sdk/android/src/jni/audio_device/audio_record_jni.h"
+#include "sdk/android/src/jni/audio_device/audio_track_jni.h"
+#include "sdk/android/src/jni/audio_device/opensles_player.h"
+#include "sdk/android/src/jni/audio_device/opensles_recorder.h"
+
+namespace webrtc {
+
+rtc::scoped_refptr<AudioDeviceModule> CreateAndroidAudioDeviceModule() {
+  RTC_LOG(INFO) << __FUNCTION__;
+  // Create an Android audio manager.
+  android_adm::AudioManager audio_manager_android;
+  // Select best possible combination of audio layers.
+  if (audio_manager_android.IsAAudioSupported()) {
+#if defined(AUDIO_DEVICE_INCLUDE_ANDROID_AAUDIO)
+    return new rtc::RefCountedObject<android_adm::AudioDeviceTemplateAndroid<
+        android_adm::AAudioRecorder, android_adm::AAudioPlayer>>(
+        AudioDeviceModule::kAndroidAAudioAudio);
+#endif
+  } else if (audio_manager_android.IsLowLatencyPlayoutSupported() &&
+             audio_manager_android.IsLowLatencyRecordSupported()) {
+    // Use OpenSL ES for both playout and recording.
+    return new rtc::RefCountedObject<android_adm::AudioDeviceTemplateAndroid<
+        android_adm::OpenSLESRecorder, android_adm::OpenSLESPlayer>>(
+        AudioDeviceModule::kAndroidOpenSLESAudio);
+  } else if (audio_manager_android.IsLowLatencyPlayoutSupported() &&
+             !audio_manager_android.IsLowLatencyRecordSupported()) {
+    // Use OpenSL ES for output on devices that only supports the
+    // low-latency output audio path.
+    // This combination provides low-latency output audio and at the same
+    // time support for HW AEC using the AudioRecord Java API.
+    return new rtc::RefCountedObject<android_adm::AudioDeviceTemplateAndroid<
+        android_adm::AudioRecordJni, android_adm::OpenSLESPlayer>>(
+        AudioDeviceModule::kAndroidJavaInputAndOpenSLESOutputAudio);
+  } else {
+    // Use Java-based audio in both directions when low-latency output is
+    // not supported.
+    return new rtc::RefCountedObject<android_adm::AudioDeviceTemplateAndroid<
+        android_adm::AudioRecordJni, android_adm::AudioTrackJni>>(
+        AudioDeviceModule::kAndroidJavaAudio);
+  }
+  RTC_LOG(LS_ERROR) << "The requested audio layer is not supported";
+  return nullptr;
+}
+
+}  // namespace webrtc

sdk/android/native_api/audio_device_module/audio_device_android.h

@@ -0,0 +1,22 @@
+/*
+ *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef SDK_ANDROID_NATIVE_API_AUDIO_DEVICE_MODULE_AUDIO_DEVICE_ANDROID_H_
+#define SDK_ANDROID_NATIVE_API_AUDIO_DEVICE_MODULE_AUDIO_DEVICE_ANDROID_H_
+
+#include "modules/audio_device/include/audio_device.h"
+
+namespace webrtc {
+
+rtc::scoped_refptr<AudioDeviceModule> CreateAndroidAudioDeviceModule();
+
+}  // namespace webrtc
+
+#endif  // SDK_ANDROID_NATIVE_API_AUDIO_DEVICE_MODULE_AUDIO_DEVICE_ANDROID_H_