Apply gn format with 'sources' sorting to src/

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/ui.gni")
 import("//testing/test.gni")
 
 static_library("dom4_keycode_converter") {
   sources = [
     "keycodes/dom3/dom_code.h",
@@ skipping 335 matching lines @@
   }
 
   if (use_aura) {
     sources += [ "gestures/gesture_provider_aura_unittest.cc" ]
   }
 }
 
 if (is_nacl) {
   source_set("latency_info") {
     sources = [
+      "ipc/latency_info_param_traits.cc",
+      "ipc/latency_info_param_traits.h",
       "latency_info.cc",
       "latency_info.h",
-      "ipc/latency_info_param_traits.cc",
-      "ipc/latency_info_param_traits.h",
     ]
   }
 }