Improve GN header checker, make //ui pass.

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")
 
 static_library("dom4_keycode_converter") {
   sources = [
     "keycodes/dom4/keycode_converter.cc",
     "keycodes/dom4/keycode_converter.h",
@@ skipping 28 matching lines @@
     "latency_info.cc",
     "latency_info.h",
     "touchscreen_device.cc",
     "touchscreen_device.h",
   ]
 
   defines = [ "EVENTS_BASE_IMPLEMENTATION" ]
 
   deps = [
     ":dom4_keycode_converter",
-    "//base",
     "//base/third_party/dynamic_annotations",
     "//skia",
+  ]
+
+  public_deps = [
+    "//base",
     "//ui/events/platform",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
-  forward_dependent_configs_from = [ "//ui/gfx" ]
-
   if (use_x11) {
     configs += [ "//build/config/linux:x11" ]
 
     sources += [
       "keycodes/keyboard_code_conversion_x.cc",
       "keycodes/keyboard_code_conversion_x.h",
       "x/device_data_manager_x11.cc",
       "x/device_data_manager_x11.h",
       "x/device_list_cache_x.cc",
       "x/device_list_cache_x.h",
       "x/hotplug_event_handler_x11.cc",
       "x/hotplug_event_handler_x11.h",
       "x/keysym_to_unicode.cc",
       "x/keysym_to_unicode.h",
       "x/touch_factory_x11.cc",
       "x/touch_factory_x11.h",
     ]
+
+    deps += [ "//ui/gfx/x" ]
   }
 }
 
 component("events") {
   sources = [
     "cocoa/cocoa_event_utils.h",
     "cocoa/cocoa_event_utils.mm",
     "cocoa/events_mac.mm",
     "event.cc",
     "event.h",
@@ skipping 11 matching lines @@
     "event_target_iterator.h",
     "event_targeter.cc",
     "event_targeter.h",
     "event_utils.cc",
     "event_utils.h",
     "events_export.h",
     "events_stub.cc",
     "gestures/gesture_recognizer_impl_mac.cc",
     "gestures/gesture_types.h",
     "win/events_win.cc",
-    "x/events_x.cc",
   ]
 
   defines = [ "EVENTS_IMPLEMENTATION" ]
 
+  public_deps = [
+    ":events_base",
+  ]
   deps = [
     ":dom4_keycode_converter",
-    ":events_base",
     ":gesture_detection",
     "//base/third_party/dynamic_annotations",
     "//skia",
     "//ui/gfx",
     "//ui/gfx/geometry",
   ]
 
   forward_dependent_configs_from = [ ":events_base" ]
 
   if (use_x11) {
+    sources += [ "x/events_x.cc" ]
     configs += [
       "//build/config/linux:glib",
       "//build/config/linux:x11",
     ]
-  } else {
-    sources -= [
-      "x/events_x.cc",
-    ]
+    deps += [ "//ui/gfx/x" ]
   }
 
   if (!is_chromeos && is_linux) {
     sources += [
       "linux/text_edit_command_auralinux.cc",
       "linux/text_edit_command_auralinux.h",
       "linux/text_edit_key_bindings_delegate_auralinux.cc",
       "linux/text_edit_key_bindings_delegate_auralinux.h",
     ]
   }
@@ skipping 75 matching lines @@
 }
 
 source_set("test_support") {
   sources = [
     "test/cocoa_test_event_utils.h",
     "test/cocoa_test_event_utils.mm",
     "test/event_generator.cc",
     "test/event_generator.h",
     "test/events_test_utils.cc",
     "test/events_test_utils.h",
-    "test/events_test_utils_x11.cc",
-    "test/events_test_utils_x11.h",
     "test/mock_motion_event.cc",
     "test/mock_motion_event.h",
     "test/platform_event_waiter.cc",
     "test/platform_event_waiter.h",
     "test/test_event_handler.cc",
     "test/test_event_handler.h",
     "test/test_event_processor.cc",
     "test/test_event_processor.h",
     "test/test_event_target.cc",
     "test/test_event_target.h",
   ]
 
-  deps = [
+  public_deps = [
     ":events",
     ":events_base",
     ":gesture_detection",
+  ]
+  deps = [
     "//base",
     "//skia",
     "//ui/events/platform",
     "//ui/gfx/geometry",
   ]
 
   if (is_ios) {
     sources -= [
       "test/cocoa_test_event_utils.h",
       "test/cocoa_test_event_utils.mm",
     ]
   }
 
-  if (!use_x11) {
-    sources -= [
+  if (use_x11) {
+    sources += [
       "test/events_test_utils_x11.cc",
       "test/events_test_utils_x11.h",
     ]
+    deps += [ "//ui/gfx/x" ]
   }
 }
 
 test("events_unittests") {
   sources = [
     "cocoa/events_mac_unittest.mm",
     "event_dispatcher_unittest.cc",
     "event_processor_unittest.cc",
     "event_rewriter_unittest.cc",
     "event_unittest.cc",
@@ skipping 39 matching lines @@
       "ozone/evdev/touch_event_converter_evdev_unittest.cc",
     ]
   }
 
   if (use_aura) {
     sources += [
       "gestures/gesture_provider_aura_unittest.cc",
     ]
   }
 }