Improve GN header checker, make //ui pass.

ui/events/platform/x11/BUILD.gn

Index: ui/events/platform/x11/BUILD.gn
diff --git a/ui/events/platform/x11/BUILD.gn b/ui/events/platform/x11/BUILD.gn
index 6182d0e7955768c1049df097222418b8a9d04d4b..3ed70b92c67d00f8bed576e3f948aed63e8f9967 100644
--- a/ui/events/platform/x11/BUILD.gn
+++ b/ui/events/platform/x11/BUILD.gn
@@ -12,15 +12,11 @@ component("x11") {
     "x11_event_source_libevent.cc",
   ]
 
-  defines = [
-    "EVENTS_IMPLEMENTATION",
-  ]
+  defines = [ "EVENTS_IMPLEMENTATION" ]
 
-  configs += [
-    "//build/config/linux:x11",
-  ]
+  configs += [ "//build/config/linux:x11" ]
 
-  deps = [
+  public_deps = [
     "//ui/events",
     "//ui/events:events_base",
     "//ui/events/platform",
@@ -28,16 +24,10 @@ component("x11") {
   ]
 
   if (is_linux) {
-    sources -= [
-      "x11_event_source_libevent.cc",
-    ]
+    sources -= [ "x11_event_source_libevent.cc" ]
 
-    configs += [
-      "//build/config/linux:glib",
-    ]
+    configs += [ "//build/config/linux:glib" ]
   } else {
-    sources -= [
-      "x11_event_source_glib.cc",
-    ]
+    sources -= [ "x11_event_source_glib.cc" ]
   }
 }