[DeviceLight] Browser+java part

content/renderer/device_sensors/device_light_event_pump.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 "content/renderer/device_sensors/device_light_event_pump.h"
 
 #include "content/common/device_sensors/device_light_messages.h"
 #include "content/public/renderer/render_thread.h"
 #include "third_party/WebKit/public/platform/WebDeviceLightListener.h"
 
@@ skipping 19 matching lines @@
   IPC_BEGIN_MESSAGE_MAP(DeviceLightEventPump, message)
     IPC_MESSAGE_HANDLER(DeviceLightMsg_DidStartPolling, OnDidStart)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
 }
 
 void DeviceLightEventPump::FireEvent() {
   DCHECK(listener());
   DeviceLightData data;
-  bool did_return_light_data = reader_->GetLatestData(&data);
-  if (did_return_light_data && data.value != last_seen_data_) {
+  if (reader_->GetLatestData(&data) && ShouldFireEvent(data.value)) {
     last_seen_data_ = data.value;
     listener()->didChangeDeviceLight(data.value);
   }
 }
 
+bool DeviceLightEventPump::ShouldFireEvent(double lux) const {
+  if (lux < 0)
+    return false;
+
+  if (lux != last_seen_data_ || lux == std::numeric_limits<double>::infinity())

[timvolodine, 2014/09/08 15:20:19]

could you add a comment regarding why infinity is special?
maybe something like this looks cleaner:
// ..
if (lux == infinity)
  return true;

return lux != last_seen_data;

[timvolodine, 2014/09/08 15:20:19]

also a unit test for this case would be desirable

[riju_, 2014/09/09 14:01:18]

Done.

[riju_, 2014/09/09 14:01:18]

Done.

+    return true;
+
+  return false;
+}
+
 bool DeviceLightEventPump::InitializeReader(base::SharedMemoryHandle handle) {
   if (!reader_)
     reader_.reset(new DeviceLightSharedMemoryReader());
   return reader_->Initialize(handle);
 }
 
 void DeviceLightEventPump::SendStartMessage() {
   RenderThread::Get()->Send(new DeviceLightHostMsg_StartPolling());
 }
 
 void DeviceLightEventPump::SendStopMessage() {
   last_seen_data_ = -1;
   RenderThread::Get()->Send(new DeviceLightHostMsg_StopPolling());
 }
 
 void DeviceLightEventPump::SendFakeDataForTesting(void* fake_data) {
   double data = *static_cast<double*>(fake_data);
 
   listener()->didChangeDeviceLight(data);
 }
 
 }  // namespace content