[Sensors] Fix reading updates after page refresh

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

Index: third_party/WebKit/Source/modules/sensor/SensorReadingUpdater.cpp
diff --git a/third_party/WebKit/Source/modules/sensor/SensorReadingUpdater.cpp b/third_party/WebKit/Source/modules/sensor/SensorReadingUpdater.cpp
index 3d35f7da1f8c0a31755ddbe5f2056c1113818b68..88e9b91c66c96558da421f2c4653981985f470b1 100644
--- a/third_party/WebKit/Source/modules/sensor/SensorReadingUpdater.cpp
+++ b/third_party/WebKit/Source/modules/sensor/SensorReadingUpdater.cpp
@@ -22,14 +22,21 @@ void SensorReadingUpdater::enqueueAnimationFrameTask() {
 
   auto callback = WTF::bind(&SensorReadingUpdater::onAnimationFrame,

[shalamov, 2017/01/20 09:25:32]

can be moved inside if (...)

[Mikhail, 2017/01/24 12:00:18]

Done.

                             wrapWeakPersistent(this));
-  m_sensorProxy->document()->enqueueAnimationFrameTask(std::move(callback));
-  m_hasPendingAnimationFrameTask = true;
+  auto document = m_sensorProxy->document();
+  if (document) {
+    document->enqueueAnimationFrameTask(std::move(callback));
+    m_hasPendingAnimationFrameTask = true;
+  }
 }
 
 void SensorReadingUpdater::start() {
   enqueueAnimationFrameTask();
 }
 
+void SensorReadingUpdater::reset() {
+  m_hasPendingAnimationFrameTask = false;

[haraken, 2017/01/19 13:57:28]

Would you help me understand why you need to set it to false here?

Also even if you set it to false, the animation frame task is not yet canceled.
 

[shalamov, 2017/01/20 09:25:33]

haraken@ is right, looks like if task was enqueued, setting to false would not
stop consecutive "enqueue" calls when callback is called, right?

[Mikhail, 2017/01/24 12:00:18]

I thought it as just a "reset" of the internal state of the object, anyway the
latest patch does not contain it :)

+}
+
 void SensorReadingUpdater::onAnimationFrame() {
   m_hasPendingAnimationFrameTask = false;
   onAnimationFrameInternal();