Bug 1287983 part 1 - Add transitionstart/transitionrun event handlers. r=masayuki,smaug

This transitionstart and transitionrun event is defined in
editor's draft of CSS Transition Level 2.

https://drafts.csswg.org/css-transitions-2/#transition-events

MozReview-Commit-ID: 6c0GqlaOOPZ

--HG--
extra : rebase_source : 9d16572634a388da25e16096f06087e808ec57ae

dom/base/nsGkAtomList.h

@@ -938,6 +938,8 @@ GK_ATOM(ontouchend, "ontouchend")
 GK_ATOM(ontouchmove, "ontouchmove")
 GK_ATOM(ontouchcancel, "ontouchcancel")
 GK_ATOM(ontransitionend, "ontransitionend")
+GK_ATOM(ontransitionrun, "ontransitionrun")
+GK_ATOM(ontransitionstart, "ontransitionstart")
 GK_ATOM(onunderflow, "onunderflow")
 GK_ATOM(onunload, "onunload")
 GK_ATOM(onupdatefound, "onupdatefound")

dom/events/EventNameList.h

@@ -979,6 +979,14 @@ NON_IDL_EVENT(MozEdgeUICompleted,
               eSimpleGestureEventClass)
 
 // CSS Transition & Animation events:
+EVENT(transitionstart,
+      eTransitionStart,
+      EventNameType_All,
+      eTransitionEventClass)
+EVENT(transitionrun,
+      eTransitionRun,
+      EventNameType_All,
+      eTransitionEventClass)
 EVENT(transitionend,
       eTransitionEnd,
       EventNameType_All,

dom/webidl/EventHandler.webidl

@@ -132,6 +132,8 @@ interface GlobalEventHandlers {
            attribute EventHandler onanimationiteration;
            attribute EventHandler onanimationstart;
            attribute EventHandler ontransitionend;
+           attribute EventHandler ontransitionrun;
+           attribute EventHandler ontransitionstart;
 
            // CSS-Animation and CSS-Transition legacy handlers.
            // This handler isn't standard.

widget/EventMessageList.h

@@ -334,6 +334,8 @@ NS_EVENT_MESSAGE(eGestureNotify)
 NS_EVENT_MESSAGE(eScrolledAreaChanged)
 
 // CSS Transition & Animation events:
+NS_EVENT_MESSAGE(eTransitionStart)
+NS_EVENT_MESSAGE(eTransitionRun)
 NS_EVENT_MESSAGE(eTransitionEnd)
 NS_EVENT_MESSAGE(eAnimationStart)
 NS_EVENT_MESSAGE(eAnimationEnd)