Revert of Device Orientation API on Chrome OS

content/browser/device_sensors/sensor_manager_chromeos.cc

-// Copyright 2015 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/browser/device_sensors/sensor_manager_chromeos.h"
-
-#include "base/logging.h"
-#include "chromeos/accelerometer/accelerometer_reader.h"
-#include "chromeos/accelerometer/accelerometer_types.h"
-#include "ui/gfx/geometry/vector3d_f.h"
-
-namespace {
-// Conversion ratio from radians to degrees.
-const double kRad2deg = 180.0 / M_PI;
-}
-
-namespace content {
-
-SensorManagerChromeOS::SensorManagerChromeOS() : orientation_buffer_(nullptr) {
-}
-
-SensorManagerChromeOS::~SensorManagerChromeOS() {
-}
-
-bool SensorManagerChromeOS::StartFetchingDeviceOrientationData(
-    DeviceOrientationHardwareBuffer* buffer) {
-  DCHECK(buffer);
-  {
-    base::AutoLock autolock(orientation_buffer_lock_);
-    if (orientation_buffer_)
-      return false;
-    orientation_buffer_ = buffer;
-
-    // No compass information, so we cannot provide absolute orientation.
-    orientation_buffer_->seqlock.WriteBegin();
-    orientation_buffer_->data.absolute = false;
-    orientation_buffer_->data.hasAbsolute = true;
-    orientation_buffer_->seqlock.WriteEnd();
-  }
-
-  StartObservingAccelerometer();
-  return true;
-}
-
-bool SensorManagerChromeOS::StopFetchingDeviceOrientationData() {
-  {
-    base::AutoLock autolock(orientation_buffer_lock_);
-    if (!orientation_buffer_)
-      return false;
-    // Make sure to indicate that the sensor data is no longer available.
-    orientation_buffer_->seqlock.WriteBegin();
-    orientation_buffer_->data.allAvailableSensorsAreActive = false;
-    orientation_buffer_->seqlock.WriteEnd();
-    orientation_buffer_ = nullptr;
-  }
-
-  StopObservingAccelerometer();
-  return true;
-}
-
-void SensorManagerChromeOS::OnAccelerometerUpdated(
-    const chromeos::AccelerometerUpdate& update) {
-  base::AutoLock autolock(orientation_buffer_lock_);
-  if (!orientation_buffer_)
-    return;
-
-  chromeos::AccelerometerSource source;
-  if (update.has(chromeos::ACCELEROMETER_SOURCE_SCREEN)) {
-    source = chromeos::ACCELEROMETER_SOURCE_SCREEN;
-  } else if (update.has(chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD)) {
-    source = chromeos::ACCELEROMETER_SOURCE_ATTACHED_KEYBOARD;
-  } else {
-    return;
-  }
-
-  double x = update.get(source).x;
-  double y = update.get(source).y;
-  double z = update.get(source).z;
-
-  // Create a unit vector for trigonometry
-  // TODO(jonross): Stop reversing signs for vector components once
-  // accelerometer values have been fixed. crbug.com/431391
-  // Ternaries are to remove -0.0f which gives incorrect trigonometrical
-  // results.
-  gfx::Vector3dF data(x, y ? -y : 0.0f, z ? -z : 0.0f);
-  data.Scale(1.0f / data.Length());
-
-  // Transform accelerometer to W3C angles, using the Z-X-Y Eulerangles matrix.
-  // x = sin(gamma)
-  // y = -cos(gamma) * sin(beta)
-  // z = cos(beta) * cos(gamma)
-  // With only accelerometer alpha cannot be provided.
-  double beta = kRad2deg * atan2(data.y(), data.z());
-  double gamma = kRad2deg * asin(data.x());
-
-  // Convert beta and gamma to fit the intervals in the specification. Beta is
-  // [-180, 180) and gamma is [-90, 90).
-  if (beta >= 180.0f)
-    beta = -180.0f;
-  if (gamma >= 90.0f)
-    gamma = -90.0f;
-  orientation_buffer_->seqlock.WriteBegin();
-  orientation_buffer_->data.beta = beta;
-  orientation_buffer_->data.hasBeta = true;
-  orientation_buffer_->data.gamma = gamma;
-  orientation_buffer_->data.hasGamma = true;
-  orientation_buffer_->data.allAvailableSensorsAreActive = true;
-  orientation_buffer_->seqlock.WriteEnd();
-}
-
-void SensorManagerChromeOS::StartObservingAccelerometer() {
-  chromeos::AccelerometerReader::GetInstance()->AddObserver(this);
-}
-
-void SensorManagerChromeOS::StopObservingAccelerometer() {
-  chromeos::AccelerometerReader::GetInstance()->RemoveObserver(this);
-}
-
-}  // namespace content