Factor out ShouldIgnoreNavigation and add tests for the function

chrome/browser/chromeos/arc/intent_helper/arc_external_protocol_dialog.h

 // Copyright 2016 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_ARC_INTENT_HELPER_ARC_EXTERNAL_PROTOCOL_DIALOG_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_INTENT_HELPER_ARC_EXTERNAL_PROTOCOL_DIALOG_H_
 
 #include <string>
 #include <utility>
 
@@ skipping 13 matching lines @@
 };
 
 // Shows ARC version of the dialog. Returns true if ARC is supported, running,
 // and in a context where it is allowed to handle external protocol.
 bool RunArcExternalProtocolDialog(const GURL& url,
                                   int render_process_host_id,
                                   int routing_id,
                                   ui::PageTransition page_transition,
                                   bool has_user_gesture);
 
+bool ShouldIgnoreNavigationForTesting(ui::PageTransition page_transition);
+
 GetActionResult GetActionForTesting(
     const GURL& original_url,
     const mojo::Array<mojom::IntentHandlerInfoPtr>& handlers,
     size_t selected_app_index,
     std::pair<GURL, std::string>* out_url_and_package);
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_INTENT_HELPER_ARC_EXTERNAL_PROTOCOL_DIALOG_H_