Add an external protocol dialog for ARC

chrome/browser/chromeos/BUILD.gn

Index: chrome/browser/chromeos/BUILD.gn
diff --git a/chrome/browser/chromeos/BUILD.gn b/chrome/browser/chromeos/BUILD.gn
index b68dff1745bdeb6d5c93887bcbd342d5f2ca7a19..b2005f114edace385f1233aedd23239aa01cf7b1 100644
--- a/chrome/browser/chromeos/BUILD.gn
+++ b/chrome/browser/chromeos/BUILD.gn
@@ -212,6 +212,8 @@ source_set("chromeos") {
     "arc/arc_downloads_watcher_service.h",
     "arc/arc_enterprise_reporting_service.cc",
     "arc/arc_enterprise_reporting_service.h",
+    "arc/arc_external_protocol_dialog.cc",
+    "arc/arc_external_protocol_dialog.h",
     "arc/arc_navigation_throttle.cc",
     "arc/arc_navigation_throttle.h",
     "arc/arc_optin_uma.cc",
@@ -236,6 +238,8 @@ source_set("chromeos") {
     "arc/arc_wallpaper_service.h",
     "arc/gpu_arc_video_service_host.cc",
     "arc/gpu_arc_video_service_host.h",
+    "arc/page_transition_util.cc",
+    "arc/page_transition_util.h",
     "attestation/attestation_ca_client.cc",
     "attestation/attestation_ca_client.h",
     "attestation/attestation_policy_observer.cc",