Move Screen Rotation from MaximizeModeController to ScreenOrientationController

ui/accelerometer/accelerometer_types.cc

 // 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.
 
 #include "ui/accelerometer/accelerometer_types.h"
 
+#include <cmath>
+
 namespace ui {
 
+namespace {
+
+// The mean acceleration due to gravity on Earth in m/s^2.
+const float kMeanGravity = 9.80665f;
+
+// The maximum deviation from the acceleration expected due to gravity under
+// which to detect hinge angle and screen rotation in m/s^2
+const float kDeviationFromGravityThreshold = 1.0f;
+}
+
 AccelerometerReading::AccelerometerReading() : present(false) {
 }
 
 AccelerometerReading::~AccelerometerReading() {
 }
 
 AccelerometerUpdate::AccelerometerUpdate() {
 }
 
 AccelerometerUpdate::~AccelerometerUpdate() {
 }
 
+bool AccelerometerUpdate::IsReadingStable(AccelerometerSource source) const {
+  return has(source) &&
+         std::abs(get(source).Length() - kMeanGravity) <=
+             kDeviationFromGravityThreshold;
+}
+
 }  // namespace ui