[sensors] Ambient light sensor bindings implementation

third_party/WebKit/Source/modules/sensor/AmbientLightSensorReading.cpp

+// Copyright 2016 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 "modules/sensor/AmbientLightSensorReading.h"
+
+#include "modules/sensor/SensorProxy.h"
+
+namespace blink {
+
+AmbientLightSensorReading::AmbientLightSensorReading(const AmbientLightSensorReadingInit& init)
+    : SensorReading(nullptr)
+    , mAmbientLightSensorReadingInit(init)
+{
+}
+
+AmbientLightSensorReading::AmbientLightSensorReading(SensorProxy* proxy)
+    : SensorReading(proxy)
+    , mAmbientLightSensorReadingInit(AmbientLightSensorReadingInit())
+{
+}
+
+AmbientLightSensorReading::~AmbientLightSensorReading() = default;
+
+double AmbientLightSensorReading::illuminance() const
+{
+    if (mAmbientLightSensorReadingInit.hasIlluminance())
+        return mAmbientLightSensorReadingInit.illuminance();
+
+    if (!m_sensorProxy)
+        return 0.0;

[timvolodine, 2016/09/19 16:37:32]

is this according to spec?

+    return m_sensorProxy->reading().reading[0];
+}
+
+bool AmbientLightSensorReading::isReadingUpdated(const SensorProxy::Reading& previous) const
+{
+    if (!m_sensorProxy)
+        return false;
+    return previous.reading[0] != illuminance();
+}
+
+DEFINE_TRACE(AmbientLightSensorReading)
+{
+    SensorReading::trace(visitor);
+}
+
+} // namespace blink