Move //device/sensor impl to be part of the internal implemenation of the Device Service.

device/sensors/public/cpp/shared_memory_seqlock_reader.h

-// Copyright 2013 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_SENSORS_PUBLIC_CPP_SHARED_MEMORY_SEQLOCK_READER_H_
-#define DEVICE_SENSORS_PUBLIC_CPP_SHARED_MEMORY_SEQLOCK_READER_H_
-
-#include <stddef.h>
-
-#include <memory>
-
-#include "base/macros.h"
-#include "base/memory/shared_memory.h"
-#include "device/base/synchronization/shared_memory_seqlock_buffer.h"
-
-namespace device {
-namespace internal {
-
-class SharedMemorySeqLockReaderBase {
- protected:
-  SharedMemorySeqLockReaderBase();
-  virtual ~SharedMemorySeqLockReaderBase();
-
-  void* InitializeSharedMemory(base::SharedMemoryHandle shared_memory_handle,
-                               size_t buffer_size);
-
-  bool FetchFromBuffer(device::OneWriterSeqLock* seqlock,
-                       void* final,
-                       void* temp,
-                       void* from,
-                       size_t size);
-
-  static const int kMaximumContentionCount = 10;
-  base::SharedMemoryHandle renderer_shared_memory_handle_;
-  std::unique_ptr<base::SharedMemory> renderer_shared_memory_;
-};
-
-}  // namespace internal
-
-// Template argument Data should be a pod-like structure only containing
-// data fields, such that it is copyable by memcpy method.
-template <typename Data>
-class SharedMemorySeqLockReader
-    : private internal::SharedMemorySeqLockReaderBase {
- public:
-  SharedMemorySeqLockReader() : buffer_(0) {}
-  virtual ~SharedMemorySeqLockReader() {}
-
-  bool GetLatestData(Data* data) {
-    DCHECK(buffer_);
-    DCHECK(sizeof(*data) == sizeof(*temp_buffer_));
-    return FetchFromBuffer(&buffer_->seqlock, data, temp_buffer_.get(),
-                           &buffer_->data, sizeof(*temp_buffer_));
-  }
-
-  bool Initialize(base::SharedMemoryHandle shared_memory_handle) {
-    if (void* memory = InitializeSharedMemory(
-            shared_memory_handle,
-            sizeof(device::SharedMemorySeqLockBuffer<Data>))) {
-      buffer_ = static_cast<device::SharedMemorySeqLockBuffer<Data>*>(memory);
-      temp_buffer_.reset(new Data);
-      return true;
-    }
-    return false;
-  }
-
- private:
-  device::SharedMemorySeqLockBuffer<Data>* buffer_;
-  std::unique_ptr<Data> temp_buffer_;
-
-  DISALLOW_COPY_AND_ASSIGN(SharedMemorySeqLockReader);
-};
-
-}  // namespace device
-
-#endif  // DEVICE_SENSORS_PUBLIC_CPP_SHARED_MEMORY_SEQLOCK_READER_H_