Make "source" a required argument of AppLaunchParams and fill in the argument in all call points.

chrome/browser/ui/webui/chromeos/login/error_screen_handler.cc

Index: chrome/browser/ui/webui/chromeos/login/error_screen_handler.cc
diff --git a/chrome/browser/ui/webui/chromeos/login/error_screen_handler.cc b/chrome/browser/ui/webui/chromeos/login/error_screen_handler.cc
index b25aa16a9a345d0a7026335ae7b0febd62a04991..add8c884a8aa9bf1709c1c187de2c6b84169637b 100644
--- a/chrome/browser/ui/webui/chromeos/login/error_screen_handler.cc
+++ b/chrome/browser/ui/webui/chromeos/login/error_screen_handler.cc
@@ -15,6 +15,7 @@
 #include "chrome/browser/extensions/component_loader.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/profiles/profile_manager.h"
+#include "chrome/browser/ui/extensions/app_launch_params.h"
 #include "chrome/browser/ui/extensions/application_launch.h"
 #include "chrome/browser/ui/webui/chromeos/login/native_window_delegate.h"
 #include "chrome/browser/ui/webui/chromeos/login/network_state_informer.h"
@@ -28,6 +29,7 @@
 #include "chromeos/network/portal_detector/network_portal_detector_strategy.h"
 #include "components/user_manager/user_manager.h"
 #include "extensions/browser/extension_system.h"
+#include "extensions/common/constants.h"
 #include "grit/browser_resources.h"
 #include "ui/strings/grit/ui_strings.h"
 
@@ -218,9 +220,9 @@ void ErrorScreenHandler::HandleDiagnoseButtonClicked() {
 
   const extensions::Extension* extension = extension_service->
       GetExtensionById(extension_id, true);
-  OpenApplication(AppLaunchParams(profile, extension,
-                                  extensions::LAUNCH_CONTAINER_WINDOW,
-                                  NEW_WINDOW));
+  OpenApplication(
+      AppLaunchParams(profile, extension, extensions::LAUNCH_CONTAINER_WINDOW,
+                      NEW_WINDOW, extensions::SOURCE_CHROME_INTERNAL));
   InitAppSession(profile, extension_id);
 
   user_manager::UserManager::Get()->SessionStarted();