[DevTools] Create a Background Service view for Periodic Sync

Add a new material UI icon:
- https://material.io/tools/icons/?icon=schedule&style=baseline

The UI is hidden behind an experiment flag.

Screenshot:
- https://bugs.chromium.org/p/chromium/issues/detail?id=986437#c1

Bug: 986437
Change-Id: I744df74453e887e2ba61877b5e9e05ef2166add7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1713505
Reviewed-by: Alexei Filippov <[email protected]>
Commit-Queue: Rayan Kanso <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#680531}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 085effe8ebacd54e5e0c8c9c4e4a2f17b5a0c61c
diff --git a/front_end/main/Main.js b/front_end/main/Main.js
index e104fcc..bde28ac 100644
--- a/front_end/main/Main.js
+++ b/front_end/main/Main.js
@@ -112,6 +112,8 @@
     Runtime.experiments.register('backgroundServicesNotifications', 'Background services section for Notifications');
     Runtime.experiments.register('backgroundServicesPaymentHandler', 'Background services section for Payment Handler');
     Runtime.experiments.register('backgroundServicesPushMessaging', 'Background services section for Push Messaging');
+    Runtime.experiments.register(
+        'backgroundServicesPeriodicBackgroundSync', 'Background services section for Periodic Background Sync');
     Runtime.experiments.register('blackboxJSFramesOnTimeline', 'Blackbox JavaScript frames on Timeline', true);
     Runtime.experiments.register('emptySourceMapAutoStepping', 'Empty sourcemap auto-stepping');
     Runtime.experiments.register('inputEventsOnTimelineOverview', 'Input events on Timeline overview', true);