Special casing windows for VR orientation device

Chrome for windows does not support the relative orientation sensor, so
if we are on windows, use the absolute sensor.

Bug: 820308
Change-Id: I3630ae8417839d94bedf8901b4f1509ed8e071d0
Reviewed-on: https://chromium-review.googlesource.com/1050372
Commit-Queue: Anna Offenwanger <offenwanger@chromium.org>
Reviewed-by: Bill Orr <billorr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557947}

device/vr/orientation/orientation_device.cc

@@ -17,7 +17,6 @@
 
 namespace device {
 
-using mojom::SensorType;
 using gfx::Quaternion;
 using gfx::Vector3dF;
 
@@ -54,11 +53,8 @@ VROrientationDevice::VROrientationDevice(
     mojom::SensorProviderPtr* sensor_provider,
     base::OnceClosure ready_callback)
     : ready_callback_(std::move(ready_callback)), binding_(this) {
-  // Use RELATIVE_ORIENTATION_QUATERNION rather than
-  // ABSOLUTE_ORIENTATION_QUATERNION because compass readings can be innacurate
-  // when used indoors.
   (*sensor_provider)
-      ->GetSensor(SensorType::RELATIVE_ORIENTATION_QUATERNION,
+      ->GetSensor(kOrientationSensorType,
                   base::BindOnce(&VROrientationDevice::SensorReady,
                                  base::Unretained(this)));
 

device/vr/orientation/orientation_device.h

@@ -10,6 +10,7 @@
 #include "base/callback_forward.h"
 #include "base/macros.h"
 #include "base/threading/simple_thread.h"
+#include "build/build_config.h"
 #include "device/vr/public/mojom/vr_service.mojom.h"
 #include "device/vr/vr_device_base.h"
 #include "mojo/public/cpp/bindings/binding.h"
@@ -20,6 +21,19 @@ namespace device {
 
 class SensorReadingSharedBufferReader;
 
+// Use RELATIVE_ORIENTATION_QUATERNION rather than
+// ABSOLUTE_ORIENTATION_QUATERNION because compass readings can be inacurate
+// when used indoors, unless we're on Windows which doesn't support
+// RELATIVE_ORIENTATION_QUATERNION.
+// TODO(crbug.com/730440) If RELATIVE_ORIENTATION_QUATERNION is ever
+// implemented on Windows, use that instead.
+static constexpr mojom::SensorType kOrientationSensorType =
+#if defined(OS_WIN)
+    mojom::SensorType::ABSOLUTE_ORIENTATION_QUATERNION;
+#else
+    mojom::SensorType::RELATIVE_ORIENTATION_QUATERNION;
+#endif
+
 // This class connects the orientation sensor events to the Web VR apis.
 class DEVICE_VR_EXPORT VROrientationDevice : public VRDeviceBase,
                                              public mojom::SensorClient {

device/vr/orientation/orientation_device_provider_unittest.cc

@@ -70,16 +70,15 @@ class VROrientationDeviceProviderTest : public testing::Test {
     auto init_params = mojom::SensorInitParams::New();
     init_params->sensor = std::move(sensor_ptr_);
     init_params->default_configuration = PlatformSensorConfiguration(
-        SensorTraits<mojom::SensorType::RELATIVE_ORIENTATION_QUATERNION>::
-            kDefaultFrequency);
+        SensorTraits<kOrientationSensorType>::kDefaultFrequency);
 
     init_params->client_request = mojo::MakeRequest(&sensor_client_ptr_);
 
     init_params->memory = shared_buffer_handle_->Clone(
         mojo::SharedBufferHandle::AccessMode::READ_ONLY);
 
-    init_params->buffer_offset = SensorReadingSharedBuffer::GetOffset(
-        mojom::SensorType::RELATIVE_ORIENTATION_QUATERNION);
+    init_params->buffer_offset =
+        SensorReadingSharedBuffer::GetOffset(kOrientationSensorType);
 
     return init_params;
   }

device/vr/orientation/orientation_device_unittest.cc

@@ -100,8 +100,7 @@ class VROrientationDeviceTest : public testing::Test {
   void TearDown() override { shared_buffer_handle_.reset(); }
 
   double GetBufferOffset() {
-    return SensorReadingSharedBuffer::GetOffset(
-        mojom::SensorType::RELATIVE_ORIENTATION_QUATERNION);
+    return SensorReadingSharedBuffer::GetOffset(kOrientationSensorType);
   }
 
   void InitializeDevice(mojom::SensorInitParamsPtr params) {
@@ -154,8 +153,7 @@ class VROrientationDeviceTest : public testing::Test {
     auto init_params = mojom::SensorInitParams::New();
     init_params->sensor = std::move(sensor_ptr_);
     init_params->default_configuration = PlatformSensorConfiguration(
-        SensorTraits<mojom::SensorType::RELATIVE_ORIENTATION_QUATERNION>::
-            kDefaultFrequency);
+        SensorTraits<kOrientationSensorType>::kDefaultFrequency);
 
     init_params->client_request = mojo::MakeRequest(&sensor_client_ptr_);