Use event init dictionary in modules/device_light

Source/modules/device_light/DeviceLightEvent.cpp

 // 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 "config.h"
 #include "modules/device_light/DeviceLightEvent.h"
 
 namespace blink {
 
 DeviceLightEvent::~DeviceLightEvent()
 {
 }
 
 DeviceLightEvent::DeviceLightEvent()
     : m_value(std::numeric_limits<double>::infinity())
 {
 }
 
 DeviceLightEvent::DeviceLightEvent(const AtomicString& eventType, double value)
     : Event(eventType, true, false) // The DeviceLightEvent bubbles but is not cancelable.
     , m_value(value)
 {
 }
 
 DeviceLightEvent::DeviceLightEvent(const AtomicString& eventType, const DeviceLightEventInit& initializer)
     : Event(eventType, initializer)
-    , m_value(initializer.value)
+    , m_value(std::numeric_limits<double>::infinity())

[haraken, 2014/12/03 04:31:06]

Doesn't this change existing behavior? I guess the default value was 0 before
this CL.

[bashi, 2014/12/03 04:36:48]

This CL changes "bubbles" behavior, but doesn't changes "value" behavior. It is
(and was) initialized with positive infinity. The spec also says it should be
initialized with positive infinity.

"If the implementation is unable to report the current light level, initialize
the value attribute to positive Infinity, otherwise initialize the attribute to
the current light level."

[haraken, 2014/12/03 04:38:36]

ah, makes sense. Thanks.

 {
+    if (initializer.hasValue())

[timvolodine, 2014/12/03 12:37:51]

is this always false now?

+        m_value = initializer.value();

[timvolodine, 2014/12/03 12:37:51]

can this be initialized directly in the member initialization list?

 }
 
 const AtomicString& DeviceLightEvent::interfaceName() const
 {
     return EventNames::DeviceLightEvent;
 }
 
 } // namespace blink