Windows: Ambient Light API

TEST= http://jsfiddle.net/73v8rmex/3/ (manual)

BUG=336424

Review URL: https://codereview.chromium.org/754963006

Cr-Commit-Position: refs/heads/master@{#319060}

content/browser/device_sensors/data_fetcher_shared_memory.h

@@ -61,6 +61,7 @@ class CONTENT_EXPORT DataFetcherSharedMemory
   class SensorEventSink;
   class SensorEventSinkMotion;
   class SensorEventSinkOrientation;
+  class SensorEventSinkLight;
 
   virtual FetcherType GetType() const override;
 
@@ -72,6 +73,7 @@ class CONTENT_EXPORT DataFetcherSharedMemory
   base::win::ScopedComPtr<ISensor> sensor_inclinometer_;
   base::win::ScopedComPtr<ISensor> sensor_accelerometer_;
   base::win::ScopedComPtr<ISensor> sensor_gyrometer_;
+  base::win::ScopedComPtr<ISensor> sensor_light_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(DataFetcherSharedMemory);

content/browser/device_sensors/data_fetcher_shared_memory_win.cc

@@ -18,6 +18,13 @@ namespace {
 
 const double kMeanGravity = 9.80665;
 
+void SetLightBuffer(content::DeviceLightHardwareBuffer* buffer, double lux) {
+  DCHECK(buffer);
+  buffer->seqlock.WriteBegin();
+  buffer->data.value = lux;
+  buffer->seqlock.WriteEnd();
+}
+
 }  // namespace
 
 
@@ -222,8 +229,41 @@ class DataFetcherSharedMemory::SensorEventSinkMotion
   DISALLOW_COPY_AND_ASSIGN(SensorEventSinkMotion);
 };
 
+class DataFetcherSharedMemory::SensorEventSinkLight
+    : public DataFetcherSharedMemory::SensorEventSink {
+ public:
+  explicit SensorEventSinkLight(DeviceLightHardwareBuffer* const buffer)
+      : buffer_(buffer) {}
+  virtual ~SensorEventSinkLight() {}
+
+ protected:
+  virtual bool UpdateSharedMemoryBuffer(ISensor* sensor,
+                                        ISensorDataReport* new_data) override {
+    double lux;
+    bool has_lux;
+
+    GetSensorValue(SENSOR_DATA_TYPE_LIGHT_LEVEL_LUX, new_data, &lux, &has_lux);
+
+    if(!has_lux) {
+      // Could not get lux value.
+      return false;
+    }
+
+    SetLightBuffer(buffer_, lux);
+
+    return true;
+  }
+
+ private:
+  DeviceLightHardwareBuffer* const buffer_;
+
+  DISALLOW_COPY_AND_ASSIGN(SensorEventSinkLight);
+};
+
 DataFetcherSharedMemory::DataFetcherSharedMemory()
-    : motion_buffer_(nullptr), orientation_buffer_(nullptr) {
+    : motion_buffer_(nullptr),
+      orientation_buffer_(nullptr),
+      light_buffer_(nullptr) {
 }
 
 DataFetcherSharedMemory::~DataFetcherSharedMemory() {
@@ -277,6 +317,22 @@ bool DataFetcherSharedMemory::Start(ConsumerType consumer_type, void* buffer) {
         SetBufferAvailableState(consumer_type, true);
       }
       break;
+    case CONSUMER_TYPE_LIGHT:
+      {
+        light_buffer_ = static_cast<DeviceLightHardwareBuffer*>(buffer);
+        scoped_refptr<SensorEventSink> sink(
+            new SensorEventSinkLight(light_buffer_));
+        bool sensor_light_available = RegisterForSensor(
+            SENSOR_TYPE_AMBIENT_LIGHT, sensor_light_.Receive(), sink);
+        if (sensor_light_available) {
+          SetLightBuffer(light_buffer_, -1);
+          return true;
+        }
+
+        // if no sensors are available, fire an Infinity event.
+        SetLightBuffer(light_buffer_, std::numeric_limits<double>::infinity());
+      }
+      break;
     default:
       NOTREACHED();
   }
@@ -293,6 +349,10 @@ bool DataFetcherSharedMemory::Stop(ConsumerType consumer_type) {
     case CONSUMER_TYPE_MOTION:
       motion_buffer_ = nullptr;
       return true;
+    case CONSUMER_TYPE_LIGHT:
+      SetLightBuffer(light_buffer_, -1);
+      light_buffer_ = nullptr;
+      return true;
     default:
       NOTREACHED();
   }
@@ -368,6 +428,12 @@ void DataFetcherSharedMemory::DisableSensors(ConsumerType consumer_type) {
         sensor_gyrometer_.Release();
       }
       break;
+    case CONSUMER_TYPE_LIGHT:
+      if (sensor_light_.get()) {
+        sensor_light_->SetEventSink(nullptr);
+        sensor_light_.Release();
+      }
+      break;
     default:
       NOTREACHED();
   }