Add missing .h files to .gn files that have a .cc file next to it in the gn file already.

ui/events/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 import("//ui/ozone/ozone.gni")
 
@@ skipping 430 matching lines @@
         "//ui/events/x",
         "//ui/gfx/x",
       ]
     }
 
     if (use_ozone) {
       sources += [
         "ozone/chromeos/cursor_controller_unittest.cc",
         "ozone/evdev/event_converter_evdev_impl_unittest.cc",
         "ozone/evdev/event_converter_test_util.cc",
+        "ozone/evdev/event_converter_test_util.h",
         "ozone/evdev/event_device_info_unittest.cc",
         "ozone/evdev/event_device_test_util.cc",
+        "ozone/evdev/event_device_test_util.h",
         "ozone/evdev/input_injector_evdev_unittest.cc",
         "ozone/evdev/tablet_event_converter_evdev_unittest.cc",
         "ozone/evdev/touch_event_converter_evdev_unittest.cc",
         "ozone/evdev/touch_filter/false_touch_finder_unittest.cc",
       ]
 
       if (use_xkbcommon) {
         sources += [
           "ozone/layout/keyboard_layout_engine_unittest.cc",
           "ozone/layout/xkb/xkb_keyboard_layout_engine_unittest.cc",
@@ skipping 32 matching lines @@
   generate_jar_jni("motionevent_jni_headers") {
     jni_package = "ui"
     classes = [ "android/view/MotionEvent.class" ]
   }
 
   generate_jar_jni("keyevent_jni_headers") {
     jni_package = "ui"
     classes = [ "android/view/KeyEvent.class" ]
   }
 }