Work on GN build, mostly in //ui

ui/web_dialogs/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.
+
+component("web_dialogs") {
+  sources = [
+    "web_dialog_delegate.cc",
+    "web_dialog_delegate.h",
+    "web_dialog_ui.cc",
+    "web_dialog_ui.h",
+    "web_dialog_web_contents_delegate.cc",
+    "web_dialog_web_contents_delegate.h",
+    "web_dialogs_export.h",
+  ]
+
+  defines = [ "WEB_DIALOGS_IMPLEMENTATION" ]
+
+  deps = [
+    "//base",
+    "//base/third_party/dynamic_annotations",
+    "//content/public/browser",
+    "//skia",
+  ]
+}
+
+static_library("test_support") {
+  sources = [
+    "test/test_web_contents_handler.cc",
+    "test/test_web_contents_handler.h",
+    "test/test_web_dialog_delegate.cc",
+    "test/test_web_dialog_delegate.h",
+  ]
+
+  deps = [
+    ":web_dialogs",
+    "//base",
+    "//content/public/browser",
+    "//skia",
+  ]
+}