GN: Make content_shell and webkit_unit_tests work in component build

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 271 matching lines @@
   defines = [ "UI_BASE_IMPLEMENTATION" ]
 
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
     "//base:base_static",
     "//base:i18n",
     "//net",
     "//skia",
     "//third_party/icu",
+    "//ui/events/platform",
     "//ui/events:events_base",
     "//ui/resources",
     "//ui/strings",
     "//url",
   ]
 
   if (is_ios) {
     sources += [
       "l10n/l10n_util_mac.h",
       "l10n/l10n_util_mac.mm",
@@ skipping 276 matching lines @@
       "../android/java/src/org/chromium/ui/base/LocalizationUtils.java",
       "../android/java/src/org/chromium/ui/base/ResourceBundle.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"
   }
 }