[sensors] Android platform adaptation for Generic Sensor API

device/generic_sensor/platform_sensor_provider_android.cc

+// Copyright 2016 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.
+
+#include "device/generic_sensor/platform_sensor_provider.h"
+
+#include "base/android/context_utils.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/memory/singleton.h"
+#include "device/generic_sensor/platform_sensor_android.h"
+#include "jni/PlatformSensorProvider_jni.h"
+
+using base::android::AttachCurrentThread;
+using base::android::ScopedJavaLocalRef;
+
+namespace device {
+
+class PlatformSensorProviderAndroid : public PlatformSensorProvider {
+ public:
+  PlatformSensorProviderAndroid();
+  ~PlatformSensorProviderAndroid() override;
+
+  static PlatformSensorProviderAndroid* GetInstance();
+
+ protected:
+  scoped_refptr<PlatformSensor> CreateSensorInternal(
+      mojom::SensorType type,
+      mojo::ScopedSharedBufferMapping mapping,
+      uint64_t buffer_size) override;
+
+ private:
+  // Java object org.chromium.device.sensors.PlatformSensorProvider
+  base::android::ScopedJavaGlobalRef<jobject> j_object_;
+
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorProviderAndroid);
+};
+
+// static
+PlatformSensorProvider* PlatformSensorProvider::GetInstance() {
+  return PlatformSensorProviderAndroid::GetInstance();
+}
+
+// static
+PlatformSensorProviderAndroid* PlatformSensorProviderAndroid::GetInstance() {
+  return base::Singleton<
+      PlatformSensorProviderAndroid,
+      base::LeakySingletonTraits<PlatformSensorProviderAndroid>>::get();
+}
+
+PlatformSensorProviderAndroid::PlatformSensorProviderAndroid() {
+  JNIEnv* env = AttachCurrentThread();
+  j_object_.Reset(Java_PlatformSensorProvider_create(
+      env, base::android::GetApplicationContext()));
+}
+
+PlatformSensorProviderAndroid::~PlatformSensorProviderAndroid() = default;
+
+scoped_refptr<PlatformSensor>
+PlatformSensorProviderAndroid::CreateSensorInternal(
+    mojom::SensorType type,
+    mojo::ScopedSharedBufferMapping mapping,
+    uint64_t buffer_size) {
+  JNIEnv* env = AttachCurrentThread();
+  ScopedJavaLocalRef<jobject> sensor = Java_PlatformSensorProvider_createSensor(
+      env, j_object_.obj(), static_cast<jint>(type));
+
+  if (!sensor.obj())
+    return nullptr;
+
+  return new PlatformSensorAndroid(type, std::move(mapping), buffer_size, this,
+                                   sensor);
+}
+
+}  // namespace device