Remove the hard_dep flag in GN.

ui/base/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")
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
@@ skipping 485 matching lines @@
     sources -= [
       "clipboard/clipboard_aura.cc",
     ]
   }
 
   if (is_android || is_ios) {
     sources -= [
       "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") {
   sources = [
     "test/ui_controls.h",
     "test/ui_controls_aura.cc",
     "test/ui_controls_internal_win.cc",
     "test/ui_controls_internal_win.h",
     "test/ui_controls_mac.mm",
     "test/ui_controls_win.cc",
@@ skipping 24 matching lines @@
       "../android/java/src/org/chromium/ui/base/DeviceFormFactor.java",
       "../android/java/src/org/chromium/ui/base/LocalizationUtils.java",
       "../android/java/src/org/chromium/ui/base/SelectFileDialog.java",
       "../android/java/src/org/chromium/ui/base/TouchDevice.java",
       "../android/java/src/org/chromium/ui/base/ViewAndroid.java",
       "../android/java/src/org/chromium/ui/base/WindowAndroid.java",
     ]
     jni_package = "base"
   }
 }