[sensors] Android platform adaptation for Generic Sensor API

device/generic_sensor/platform_sensor_android.h

+// 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.
+
+#ifndef DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_ANDROID_H_
+#define DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_ANDROID_H_
+
+#include "device/generic_sensor/platform_sensor.h"
+#include "base/android/scoped_java_ref.h"
+#include "base/memory/ref_counted.h"
+
+namespace base {
+class SingleThreadTaskRunner;
+}
+
+namespace device {
+
+class PlatformSensorAndroid : public PlatformSensor {
+ public:
+  // Register C++ methods exposed to Java using JNI.
+  static bool RegisterJNI(JNIEnv* env);
+
+  PlatformSensorAndroid(mojom::SensorType type,
+                        mojo::ScopedSharedBufferMapping mapping,
+                        uint64_t buffer_size,
+                        PlatformSensorProvider* provider,
+                        const base::android::JavaRef<jobject>& java_sensor);
+
+  ~PlatformSensorAndroid() override;
+  mojom::ReportingMode GetReportingMode() override;
+
+  void NotifyPlatformSensorReadingChanged(
+      JNIEnv*,
+      const base::android::JavaRef<jobject>& caller);
+  void NotifyPlatformSensorError(JNIEnv*,
+                                 const base::android::JavaRef<jobject>& caller);
+
+ protected:
+  virtual bool StartSensor(
+      const PlatformSensorConfiguration& configuration) override;

[ncarter (slow), 2016/08/29 17:37:51]

note that 'virtual' is unnecessary if 'override' is specified (and you'll get
compile errors as follows if you try:)

../../device/generic_sensor/platform_sensor_android.h:41:3: error:
[chromium-style] 'virtual' is redundant; 'override' implies 'virtual'.

I've kicked off some tryjobs, please have a look at the results.

+  virtual void StopSensor() override;
+  bool CheckSensorConfiguration(
+      const PlatformSensorConfiguration& configuration) override;
+
+ private:
+  // Java object org.chromium.device.sensors.PlatformSensor
+  base::android::ScopedJavaGlobalRef<jobject> j_object_;
+  // Task runner that is used by mojo objects for the IPC. Android sensor
+  // objects share separate handler thread that processes sensor
+  // events. Notifications from Java side are forwarded to |task_runner_|.
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  DISALLOW_COPY_AND_ASSIGN(PlatformSensorAndroid);
+};
+
+}  // namespace device
+
+#endif  // DEVICE_GENERIC_SENSOR_PLATFORM_SENSOR_ANDROID_H_