Extract a minimal subset of WebDialogUI/WebDialogDelegate from src/chrome -> src/ui/web_dialogs

chrome/browser/printing/print_dialog_cloud_unittest.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/printing/print_dialog_cloud.h"
 #include "chrome/browser/printing/print_dialog_cloud_internal.h"
 
 #include <string>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/memory/weak_ptr.h"
 #include "base/message_loop.h"
 #include "base/path_service.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "chrome/browser/printing/cloud_print/cloud_print_url.h"
+#include "chrome/browser/ui/webui/external_web_dialog_ui.h"
 #include "chrome/common/chrome_paths.h"
 #include "chrome/common/url_constants.h"
 #include "chrome/test/base/testing_profile.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_source.h"
 #include "content/public/browser/notification_types.h"
 #include "content/test/test_browser_thread.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 321 matching lines @@
   delegate_->GetWebUIMessageHandlers(&handlers);
   delegate_.reset();
   EXPECT_THAT(mock_flow_handler_.get(), NotNull());
 }
 
 // Testing for ExternalWebDialogUI needs a mock WebContents, mock
 // CloudPrintWebDialogDelegate (provided through the mock
 // tab_contents)
 
 // Testing for PrintDialogCloud needs a mock Browser.