Bug 1661640 - Add Fluent migration for bug 1660259, r=emcminn

Differential Revision: https://phabricator.services.mozilla.com/D88533

python/l10n/fluent_migrations/bug_1660259_a11y_onboarding_themes.py

@@ -0,0 +1,36 @@
+# coding=utf8
+
+# Any copyright is dedicated to the Public Domain.
+# http://creativecommons.org/publicdomain/zero/1.0/
+
+from __future__ import absolute_import
+from fluent.migrate.helpers import transforms_from
+
+
+def migrate(ctx):
+    """Bug 1660259 - Correct nav aria-label and label and description for theme buttons, part {index}."""
+
+    ctx.add_transforms(
+        "browser/browser/newtab/onboarding.ftl",
+        "browser/browser/newtab/onboarding.ftl",
+        transforms_from("""
+onboarding-multistage-theme-tooltip-automatic-2 =
+   .title = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-automatic.title") }
+onboarding-multistage-theme-description-automatic-2 =
+  .aria-description =  { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-automatic.title") }
+
+onboarding-multistage-theme-tooltip-light-2 =
+   .title = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-light.title") }
+onboarding-multistage-theme-description-light =
+  .aria-description = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-light.title") }
+
+onboarding-multistage-theme-tooltip-dark-2 =
+   .title = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-dark.title") }
+onboarding-multistage-theme-description-dark =
+  .aria-description = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-dark.title") }
+
+onboarding-multistage-theme-tooltip-alpenglow-2 =
+   .title = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-alpenglow.title") }
+onboarding-multistage-theme-description-alpenglow =
+  .aria-description = { COPY_PATTERN(from_path, "onboarding-multistage-theme-tooltip-alpenglow.title") }
+""", from_path="browser/browser/newtab/onboarding.ftl"))