fido/mac: localize Touch ID prompt strings

This adds localization for the reason string fragments used in macOS
Touch ID prompts.

The prompts display a message starting with '"Google Chrome" is trying
to ' (controlled by macOS) followed by the reason fragment (controlled
by us). The user can confirm the prompt by providing their fingerprint,
or click cancel.

Bug: 848317
Change-Id: Ibe67c197554cde0af431516d968479b0f416629e
Reviewed-on: https://chromium-review.googlesource.com/1166171
Commit-Queue: Martin Kreichgauer <[email protected]>
Reviewed-by: Jochen Eisinger <[email protected]>
Reviewed-by: Jan Wilken Dörrie <[email protected]>
Reviewed-by: Balazs Engedy <[email protected]>
Cr-Commit-Position: refs/heads/master@{#582637}
diff --git a/tools/check_grd_for_unused_strings.py b/tools/check_grd_for_unused_strings.py
index 2defb2f..773e574 100755
--- a/tools/check_grd_for_unused_strings.py
+++ b/tools/check_grd_for_unused_strings.py
@@ -155,6 +155,7 @@
       os.path.join(chrome_dir, 'renderer', 'resources',
                    'renderer_resources.grd'),
       os.path.join(device_base_dir, 'bluetooth', 'bluetooth_strings.grd'),
+      os.path.join(device_base_dir, 'fido', 'fido_strings.grd'),
       os.path.join(src_dir, 'extensions', 'strings', 'extensions_strings.grd'),
       os.path.join(src_dir, 'ui', 'resources', 'ui_resources.grd'),
       os.path.join(src_dir, 'ui', 'webui', 'resources', 'webui_resources.grd'),