Bug 1433008 - Make WidgetEvent movable. r=masayuki

The copy-assignment in this patch is used in the copy-constructor.
Note that we can't simply use '= default' implementation since we need to use
MOZ_COUNT_CTOR() in the move constructor.

MozReview-Commit-ID: 8HTMaTONBuN

--HG--
extra : rebase_source : 7da0586e0772a2d71455492412d40780c59558e5

widget/BasicEvents.h

@@ -550,6 +550,27 @@ public:
     MOZ_COUNT_CTOR(WidgetEvent);
     *this = aOther;
   }
+  WidgetEvent& operator=(const WidgetEvent& aOther) = default;
+
+  WidgetEvent(WidgetEvent&& aOther)
+    : WidgetEventTime(Move(aOther))
+    , mClass(aOther.mClass)
+    , mMessage(aOther.mMessage)
+    , mRefPoint(Move(aOther.mRefPoint))
+    , mLastRefPoint(Move(aOther.mLastRefPoint))
+    , mFocusSequenceNumber(aOther.mFocusSequenceNumber)
+    , mFlags(Move(aOther.mFlags))
+    , mSpecifiedEventType(Move(aOther.mSpecifiedEventType))
+    , mSpecifiedEventTypeString(Move(aOther.mSpecifiedEventTypeString))
+    , mTarget(Move(aOther.mTarget))
+    , mCurrentTarget(Move(aOther.mCurrentTarget))
+    , mOriginalTarget(Move(aOther.mOriginalTarget))
+    , mRelatedTarget(Move(aOther.mRelatedTarget))
+    , mPath(Move(aOther.mPath))
+  {
+    MOZ_COUNT_CTOR(WidgetEvent);
+  }
+  WidgetEvent& operator=(WidgetEvent&& aOther) = default;
 
   virtual WidgetEvent* Duplicate() const
   {