Bug 1044497 - Fix Yosemite build error (cannot initialize a parameter of type 'NSEventType' with an lvalue of type 'uint32_t') r=spohl

widget/cocoa/nsChildView.mm

@@ -1478,7 +1478,7 @@ nsresult nsChildView::SynthesizeNativeMouseEvent(nsIntPoint aPoint,
   NSPoint screenPoint = NSMakePoint(pt.x, nsCocoaUtils::FlippedScreenY(pt.y));
   NSPoint windowPoint = [[mView window] convertScreenToBase:screenPoint];
 
-  NSEvent* event = [NSEvent mouseEventWithType:aNativeMessage
+  NSEvent* event = [NSEvent mouseEventWithType:(NSEventType)aNativeMessage
                                       location:windowPoint
                                  modifierFlags:aModifierFlags
                                      timestamp:[NSDate timeIntervalSinceReferenceDate]