desktop-pwas: Fix unused variable in unit tests

Minor fix to web-app file-handler registration Windows unit tests per
comment on crrev.com/c/2002982.

Change-Id: I6a00574ac23c244c030455af821987db4f2f78b7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2016185Reviewed-by: Giovanni Ortuño Urquidi <ortuno@chromium.org>
Commit-Queue: Jesse McKenna <jessemckenna@google.com>
Cr-Commit-Position: refs/heads/master@{#734326}

chrome/browser/web_applications/components/web_app_file_handler_registration_win_unittest.cc

@@ -215,8 +215,8 @@ TEST_F(WebAppFileHandlerRegistrationWinTest, AppNameWithInvalidChars) {
       CreateDataDirectoryAndGetLauncherPathForApp(profile(), app_id,
                                                   "app_name");
 
-  RegisterFileHandlersWithOs(app_id, app_name, profile(),
-                             /*file_extensions*/ {"txt"}, /*mime_types=*/{});
+  RegisterFileHandlersWithOs(app_id, app_name, profile(), file_extensions,
+                             /*mime_types=*/{});
 
   base::ThreadPoolInstance::Get()->FlushForTesting();
   base::FilePath registered_app_path = ShellUtil::GetApplicationPathForProgId(
@@ -237,8 +237,8 @@ TEST_F(WebAppFileHandlerRegistrationWinTest, AppNameIsReservedFilename) {
   base::FilePath app_specific_launcher_path =
       CreateDataDirectoryAndGetLauncherPathForApp(profile(), app_id, "_con");
 
-  RegisterFileHandlersWithOs(app_id, app_name, profile(),
-                             /*file_extensions*/ {"txt"}, /*mime_types=*/{});
+  RegisterFileHandlersWithOs(app_id, app_name, profile(), file_extensions,
+                             /*mime_types=*/{});
 
   base::ThreadPoolInstance::Get()->FlushForTesting();
   base::FilePath registered_app_path = ShellUtil::GetApplicationPathForProgId(
@@ -262,8 +262,8 @@ TEST_F(WebAppFileHandlerRegistrationWinTest, AppNameContainsDot) {
           base::win::GetVersion() > base::win::Version::WIN7 ? "some.app.name"
                                                              : "some_app_name");
 
-  RegisterFileHandlersWithOs(app_id, app_name, profile(),
-                             /*file_extensions*/ {"txt"}, /*mime_types=*/{});
+  RegisterFileHandlersWithOs(app_id, app_name, profile(), file_extensions,
+                             /*mime_types=*/{});
 
   base::ThreadPoolInstance::Get()->FlushForTesting();
   base::FilePath registered_app_path = ShellUtil::GetApplicationPathForProgId(