Fix direction of horizontal scroll when tilting the scroll wheel on Linux Aura

ui/events/x/events_x.cc

Index: ui/events/x/events_x.cc
diff --git a/ui/events/x/events_x.cc b/ui/events/x/events_x.cc
index 17b2d3b204ca701830d54e7e823fbc8b356ce9f1..9fec9df2bf9bcf18d5f9947a3d96e0c4229a8662 100644
--- a/ui/events/x/events_x.cc
+++ b/ui/events/x/events_x.cc
@@ -526,9 +526,9 @@ gfx::Vector2d GetMouseWheelOffset(const base::NativeEvent& native_event) {
     case 5:
       return gfx::Vector2d(0, -kWheelScrollAmount);
     case 6:
-      return gfx::Vector2d(-kWheelScrollAmount, 0);
-    case 7:
       return gfx::Vector2d(kWheelScrollAmount, 0);
+    case 7:
+      return gfx::Vector2d(-kWheelScrollAmount, 0);
     default:
       return gfx::Vector2d();
   }