Reland: Refactor DeviceMotionEventPump to use //device/generic_sensor instead of //device/sensors

content/renderer/device_sensors/device_motion_event_pump.h

 // Copyright 2014 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 CONTENT_RENDERER_DEVICE_SENSORS_DEVICE_MOTION_EVENT_PUMP_H_
 #define CONTENT_RENDERER_DEVICE_SENSORS_DEVICE_MOTION_EVENT_PUMP_H_
 
 #include <memory>
+#include <utility>
+#include <vector>
 
+#include "base/bind.h"
+#include "base/bind_helpers.h"
 #include "base/macros.h"
-#include "content/renderer/device_sensors/device_sensor_event_pump.h"
-#include "content/renderer/shared_memory_seqlock_reader.h"
+#include "base/time/time.h"
+#include "base/timer/timer.h"
+#include "content/public/renderer/platform_event_observer.h"
+#include "content/renderer/render_thread_impl.h"
+#include "device/generic_sensor/public/cpp/sensor_reading.h"
+#include "device/generic_sensor/public/interfaces/sensor.mojom.h"
+#include "device/generic_sensor/public/interfaces/sensor_provider.mojom.h"
 #include "device/sensors/public/cpp/motion_data.h"
-#include "device/sensors/public/interfaces/motion.mojom.h"
-
-namespace blink {
-class WebDeviceMotionListener;
-}
+#include "mojo/public/cpp/bindings/binding.h"
+#include "third_party/WebKit/public/platform/modules/device_orientation/WebDeviceMotionListener.h"
 
 namespace content {
 
-typedef SharedMemorySeqLockReader<device::MotionData>
-    DeviceMotionSharedMemoryReader;
-
 class CONTENT_EXPORT DeviceMotionEventPump
-    : public DeviceSensorMojoClientMixin<
-          DeviceSensorEventPump<blink::WebDeviceMotionListener>,
-          device::mojom::MotionSensor> {
+    : NON_EXPORTED_BASE(
+          public PlatformEventObserver<blink::WebDeviceMotionListener>) {
  public:
   explicit DeviceMotionEventPump(RenderThread* thread);
   ~DeviceMotionEventPump() override;
 
-  // PlatformEventObserver.
+  // PlatformEventObserver:
+  void Start(blink::WebPlatformEventListener* listener) override;
+  void Stop() override;
+  void SendStartMessage() override;
+  void SendStopMessage() override;
   void SendFakeDataForTesting(void* fake_data) override;
 
  protected:
-  void FireEvent() override;
-  bool InitializeReader(base::SharedMemoryHandle handle) override;
+  // Default rate for firing events.
+  static constexpr int kDefaultPumpFrequencyHz = 60;
+  static constexpr int kDefaultPumpDelayMicroseconds =
+      base::Time::kMicrosecondsPerSecond / kDefaultPumpFrequencyHz;
 
-  std::unique_ptr<DeviceMotionSharedMemoryReader> reader_;
+  struct CONTENT_EXPORT SensorEntry : public device::mojom::SensorClient {
+    SensorEntry(DeviceMotionEventPump* pump,
+                device::mojom::SensorType sensor_type);
+    ~SensorEntry() override;
+
+    // device::mojom::SensorClient:
+    void RaiseError() override;
+    void SensorReadingChanged() override;
+
+    // Mojo callback for SensorProvider::GetSensor().
+    void OnSensorCreated(device::mojom::SensorInitParamsPtr params,
+                         device::mojom::SensorClientRequest client_request);
+
+    // Mojo callback for Sensor::AddConfiguration().
+    void OnSensorAddConfiguration(bool success);
+
+    void HandleSensorError();
+
+    bool SensorReadingCouldBeRead();
+
+    DeviceMotionEventPump* event_pump;
+    device::mojom::SensorPtr sensor;
+    device::mojom::SensorType type;
+    device::mojom::ReportingMode mode;
+    device::PlatformSensorConfiguration default_config;
+    mojo::ScopedSharedBufferHandle shared_buffer_handle;
+    mojo::ScopedSharedBufferMapping shared_buffer;
+    device::SensorReading reading;
+    std::pair<double, double> frequency_limits;
+    mojo::Binding<device::mojom::SensorClient> client_binding;
+  };
+
+  friend struct SensorEntry;
+
+  virtual void FireEvent();
+
+  void DidStart();
+
+  SensorEntry accelerometer_;
+  SensorEntry linear_acceleration_sensor_;
+  SensorEntry gyroscope_;
+  int pump_delay_microseconds_;
+
+ private:
+  // The pump is a tri-state automaton with allowed transitions as follows:
+  // STOPPED -> PENDING_START
+  // PENDING_START -> RUNNING
+  // PENDING_START -> STOPPED
+  // RUNNING -> STOPPED
+  enum class PumpState { STOPPED, RUNNING, PENDING_START };
+
+  bool CanStart() const;
+  void GetDataFromSharedMemory(device::MotionData* data);
+  void GetSensor(SensorEntry* sensor_entry);
+  void HandleSensorProviderError();
+
+  mojo::InterfacePtr<device::mojom::SensorProvider> sensor_provider_;
+  PumpState state_;
+  base::RepeatingTimer timer_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceMotionEventPump);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_DEVICE_SENSORS_DEVICE_MOTION_EVENT_PUMP_H_