Replace device_sensor browsertest by service unittest.

content/renderer/shared_memory_seqlock_reader.cc

-// 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.
-
-#include "content/renderer/shared_memory_seqlock_reader.h"
-
-namespace content {
-namespace internal {
-
-SharedMemorySeqLockReaderBase::SharedMemorySeqLockReaderBase() { }
-
-SharedMemorySeqLockReaderBase::~SharedMemorySeqLockReaderBase() { }
-
-void*
-SharedMemorySeqLockReaderBase::InitializeSharedMemory(
-    base::SharedMemoryHandle shared_memory_handle, size_t buffer_size) {
-  renderer_shared_memory_handle_ = shared_memory_handle;
-  if (!base::SharedMemory::IsHandleValid(renderer_shared_memory_handle_))
-    return 0;
-  renderer_shared_memory_.reset(new base::SharedMemory(
-      renderer_shared_memory_handle_, true));
-
-  return (renderer_shared_memory_->Map(buffer_size))
-      ? renderer_shared_memory_->memory()
-      : 0;
-}
-
-bool SharedMemorySeqLockReaderBase::FetchFromBuffer(
-    device::OneWriterSeqLock* seqlock,
-    void* final,
-    void* temp,
-    void* from,
-    size_t size) {
-  if (!base::SharedMemory::IsHandleValid(renderer_shared_memory_handle_))
-    return false;
-
-  // Only try to read this many times before failing to avoid waiting here
-  // very long in case of contention with the writer.
-  int contention_count = -1;
-  base::subtle::Atomic32 version;
-  do {
-    version = seqlock->ReadBegin();
-    memcpy(temp, from, size);
-    ++contention_count;
-    if (contention_count == kMaximumContentionCount)
-      break;
-  } while (seqlock->ReadRetry(version));
-
-  if (contention_count >= kMaximumContentionCount) {
-    // We failed to successfully read, presumably because the hardware
-    // thread was taking unusually long. Don't copy the data to the output
-    // buffer, and simply leave what was there before.
-    return false;
-  }
-
-  // New data was read successfully, copy it into the output buffer.
-  memcpy(final, temp, size);
-  return true;
-}
-
-}  // namespace internal
-}  // namespace content