Use high precision timestamp for Event.timestamp

Source/core/events/Event.h

Index: Source/core/events/Event.h
diff --git a/Source/core/events/Event.h b/Source/core/events/Event.h
index f0ee9c3637b3875a633d56950d83e070999912c5..18cbf4c236e5d1b657fb6c71daf8cf0b41b9c08f 100644
--- a/Source/core/events/Event.h
+++ b/Source/core/events/Event.h
@@ -122,7 +122,10 @@ public:
 
     bool bubbles() const { return m_canBubble; }
     bool cancelable() const { return m_cancelable; }
-    DOMTimeStamp timeStamp() const { return m_createTime; }
+
+    // Event creation timestamp in milliseconds
+    double timeStamp() const;

[dtapuska, 2015/09/18 16:04:42]

I think there should be a specific call for getting the timestamp from bindings
that you then apply the precision loss calcaulation to.

So that if native code calls this; the timestamp is reflected to the current
time. (Currently there is uiCreateTime which native code can get at the time).

[majidvp, 2015/09/18 17:43:33]

Agreed. I like to keep timeStamp() to be the method used by DOM that applies
precision filtering. This way it is easy to correspond it with IDL. I will use a
different naming for platform timestamp methods. 

+    double timeStampForPlatformInSeconds() const;

[Rick Byers, 2015/09/18 15:56:32]

nit: add comment for the new method (i.e. what "for platform" means).

[majidvp, 2015/09/18 17:43:34]

Acknowledged.

 
     void stopPropagation() { m_propagationStopped = true; }
     void stopImmediatePropagation() { m_immediatePropagationStopped = true; }
@@ -225,7 +228,7 @@ private:
     DOMTimeStamp m_createTime;
     RefPtrWillBeMember<Event> m_underlyingEvent;
     OwnPtrWillBeMember<EventPath> m_eventPath;
-    double m_uiCreateTime; // For input events, the time the event was recorded by the UI.
+    double m_uiCreateTime; // For input events, the time the event was recorded by the UI in seconds.

[dtapuska, 2015/09/18 16:04:42]

When indicating time; be sure to reference what clock. ie; monotonic clock.

[majidvp, 2015/09/18 17:43:34]

Acknowledged.

 };
 
 #define DEFINE_EVENT_TYPE_CASTS(typeName) \