IPC::ParamTraits for ui::Event (towards ui::Events over mojo IPC)

ui/events/BUILD.gn

Index: ui/events/BUILD.gn
diff --git a/ui/events/BUILD.gn b/ui/events/BUILD.gn
index 779d14d8d7917f864d554ede4b76cd1c5a7ca043..57428cbdfae276aef9f3112e1281d9ae665999b7 100644
--- a/ui/events/BUILD.gn
+++ b/ui/events/BUILD.gn
@@ -67,6 +67,7 @@ component("events_base") {
 
   public_deps = [
     "//base",
+    "//ipc:ipc",
     "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
@@ -353,6 +354,7 @@ test("events_unittests") {
     "gesture_detection/touch_disposition_gesture_filter_unittest.cc",
     "gesture_detection/velocity_tracker_unittest.cc",
     "gestures/fling_curve_unittest.cc",
+    "ipc/event_param_traits_unittest.cc",
     "ipc/latency_info_param_traits_unittest.cc",
     "keycodes/dom/keycode_converter_unittest.cc",
     "keycodes/keyboard_code_conversion_unittest.cc",