Reland of [sensors] Ambient light sensor bindings implementation

third_party/WebKit/Source/modules/sensor/SensorReading.h

Index: third_party/WebKit/Source/modules/sensor/SensorReading.h
diff --git a/third_party/WebKit/Source/modules/sensor/SensorReading.h b/third_party/WebKit/Source/modules/sensor/SensorReading.h
index 2eaf7e6a177db48e75962b885ee31ae8b643de3d..42a4640a3df74c52ca4c662575f64fc8d99f3a16 100644
--- a/third_party/WebKit/Source/modules/sensor/SensorReading.h
+++ b/third_party/WebKit/Source/modules/sensor/SensorReading.h
@@ -16,7 +16,7 @@ class ExecutionContext;
 class ScriptState;
 
 class SensorReading
-    : public GarbageCollected<SensorReading>
+    : public GarbageCollectedMixin

[haraken, 2016/09/21 14:27:51]

Why do you need to make this a GC mixin? Can you just keep it as
GarbageCollected<>? Then AmbientLightSensorReading doesn't need to inherit from
GarbageCollected<>.

[shalamov, 2016/09/22 06:33:39]

Member AmbientLightSensorReadingInit mAmbientLightSensorReadingInit; in
AmbientLightSensorReading requires finalization, that was the reason why I made
base class a mixin. All other concrete sensors would also have similar members,
so that the reading can be constructed from JS context.

[haraken, 2016/09/22 13:55:05]

Can you just make SensorReading GarbageCollectedFinalized?

A GC mixin makes things complicated and slower, so we should avoid using it
unless necessary.

[shalamov, 2016/09/22 15:15:09]

Done.

     , public ScriptWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public: