Update AccelerometerReader to support separate iio devices

ash/content/display/screen_orientation_controller_chromeos.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 "ash/content/display/screen_orientation_controller_chromeos.h"
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_info.h"
 #include "ash/display/display_manager.h"
 #include "ash/rotator/screen_rotation_animator.h"
@@ skipping 326 matching lines @@
   gfx::Vector3dF lid_flattened(lid.x, lid.y, 0.0f);
   float lid_flattened_length = lid_flattened.Length();
   // When the lid is close to being flat, don't change rotation as it is too
   // sensitive to slight movements.
   if (lid_flattened_length < kMinimumAccelerationScreenRotation)
     return;
 
   // The reference vector is the angle of gravity when the device is rotated
   // clockwise by 45 degrees. Computing the angle between this vector and
   // gravity we can easily determine the expected display rotation.
-  static const gfx::Vector3dF rotation_reference(-1.0f, -1.0f, 0.0f);
+  static const gfx::Vector3dF rotation_reference(-1.0f, 1.0f, 0.0f);
 
   // Set the down vector to match the expected direction of gravity given the
   // last configured rotation. This is used to enforce a stickiness that the
   // user must overcome to rotate the display and prevents frequent rotations
   // when holding the device near 45 degrees.
   gfx::Vector3dF down(0.0f, 0.0f, 0.0f);
   if (current_rotation_ == gfx::Display::ROTATE_0)
+    down.set_y(1.0f);
+  else if (current_rotation_ == gfx::Display::ROTATE_90)
+    down.set_x(1.0f);
+  else if (current_rotation_ == gfx::Display::ROTATE_180)
     down.set_y(-1.0f);
-  else if (current_rotation_ == gfx::Display::ROTATE_90)
+  else
     down.set_x(-1.0f);
-  else if (current_rotation_ == gfx::Display::ROTATE_180)
-    down.set_y(1.0f);
-  else
-    down.set_x(1.0f);
 
   // Don't rotate if the screen has not passed the threshold.
   if (gfx::AngleBetweenVectorsInDegrees(down, lid_flattened) <
       kDisplayRotationStickyAngleDegrees) {
     return;
   }
 
   float angle = gfx::ClockwiseAngleBetweenVectorsInDegrees(
-      rotation_reference, lid_flattened, gfx::Vector3dF(0.0f, 0.0f, -1.0f));
+      rotation_reference, lid_flattened, gfx::Vector3dF(0.0f, 0.0f, 1.0f));
 
-  gfx::Display::Rotation new_rotation = gfx::Display::ROTATE_90;
+  gfx::Display::Rotation new_rotation = gfx::Display::ROTATE_270;
   if (angle < 90.0f)
     new_rotation = gfx::Display::ROTATE_0;
   else if (angle < 180.0f)
-    new_rotation = gfx::Display::ROTATE_270;
+    new_rotation = gfx::Display::ROTATE_90;
   else if (angle < 270.0f)
     new_rotation = gfx::Display::ROTATE_180;
 
   if (new_rotation != current_rotation_ &&
-      IsRotationAllowedInLockedState(new_rotation))
+      IsRotationAllowedInLockedState(new_rotation)) {
     SetDisplayRotation(new_rotation,
                        gfx::Display::ROTATION_SOURCE_ACCELEROMETER);
+  }
 }
 
 void ScreenOrientationController::LoadDisplayRotationProperties() {
   DisplayManager* display_manager = Shell::GetInstance()->display_manager();
   if (!display_manager->registered_internal_display_rotation_lock())
     return;
   SetDisplayRotation(display_manager->registered_internal_display_rotation(),
                      gfx::Display::ROTATION_SOURCE_ACCELEROMETER);
   SetRotationLocked(true);
 }
@@ skipping 38 matching lines @@
 }
 
 bool ScreenOrientationController::CanRotateInLockedState() {
   return rotation_locked_orientation_ ==
              blink::WebScreenOrientationLockLandscape ||
          rotation_locked_orientation_ ==
              blink::WebScreenOrientationLockPortrait;
 }
 
 }  // namespace ash