Run chrome_proxy_service_test.dart everyday at 8 AM PST (#2098)

Author: elliette

.github/workflows/daily_testing.yml

@@ -0,0 +1,36 @@
+# A CI workflow to run tests on a daily cron job.
+
+name: Daily Testing
+
+on:
+  schedule:
+    - cron: '00 14 * * *' # Everyday at 3:00 PM UTC (8:00 AM PST)
+
+jobs:
+  daily_testing:
+    name: Daily Testing
+    runs-on: ubuntu-latest
+    steps:
+      - name: Setup Dart SDK
+        uses: dart-lang/setup-dart@d6a63dab3335f427404425de0fbfed4686d93c4f
+        with:
+          sdk: main
+      - id: checkout
+        name: Checkout repository
+        uses: actions/checkout@8f4b7f84864484a7bf31766abe9204da3cbe65b3
+      - id: dwds_pub_upgrade
+        name: dwds; dart pub upgrade
+        run: dart pub upgrade
+        if: "always() && steps.checkout.conclusion == 'success'"
+        working-directory: dwds
+      - id: dwds_daily_tests
+        name: "dwds; dart test --tags=daily"
+        run: "dart test --tags=daily"
+        if: "always() && steps.dwds_pub_upgrade.conclusion == 'success'"
+        working-directory: dwds
+      - name: "Notify failure"
+        if: "always() && steps.dwds_daily_tests.conclusion == 'failure'"
+        run: |
+          curl -H "Content-Type: application/json" -X POST -d \
+            "{'text':'Daily Webdev tests failed! ${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/actions/runs/${GITHUB_RUN_ID}'}" \
+            "${{ secrets.WEBDEV_NOTIFICATION_CHAT_WEBHOOK }}"

dwds/dart_test.yaml

@@ -3,3 +3,4 @@ retry: 3
 
 tags:
   extension:  # Extension tests require configuration, so we may exclude.
+  daily: # Daily tests also run on a scheduled daily cron job.

dwds/test/chrome_proxy_service_test.dart

@@ -3,6 +3,7 @@
 // BSD-style license that can be found in the LICENSE file.
 
 @TestOn('vm')
+@Tags(['daily'])
 @Timeout(Duration(minutes: 2))
 import 'dart:async';
 import 'dart:convert';