Remove the hard_dep flag in GN.

ui/base/BUILD.gn

Index: ui/base/BUILD.gn
diff --git a/ui/base/BUILD.gn b/ui/base/BUILD.gn
index a0eca8834a0f3beb2e838558535965823f43a59f..c1d8714878614f716cb5c317f0f646adee29d720 100644
--- a/ui/base/BUILD.gn
+++ b/ui/base/BUILD.gn
@@ -503,14 +503,6 @@ component("ui_base") {
       "device_form_factor_desktop.cc",
     ]
   }
-
-  # TODO(GYP): Port this to GN.
-  #if (use_system_icu) {
-    # When using the system icu, the icu targets generate shim headers
-    # which are included by public headers in the ui target, so we need
-    # ui to be a hard dependency for all its users.
-    #'hard_dependency': 1,
-  #}
 }
 
 source_set("ui_base_test_support") {