[OnionSoup] Use mojom NotificationData instead of WebNotificationData inside Blink

This CL is part of Onion Soup effort for Notification APIs, trying to
use blink::mojom::blink::NotificationData everywhere instead of
blink::WebNotificationData inside Blink.

Also, this CL removes typemapping between blink::WebNotificationData and
blink.mojom.NotificationData, thus building notification.mojom no longer
needs to depend on WebXXX types, which makes it possible for us to move
notification.mojom into blink/public/mojom/notifications/ for next step,
further, notification.mojom movement will facilitate moving
content/common/service_worker/service_worker.mojom into
blink/public/mojom/ in future.

After this CL, the only usage of blink::WebNotificationData is to carry
notification data from Content layer into Blink, which is dispatched via
content.mojom.ServiceWorker.DispatchNotification{Click, Close}Event.

BUG=595685,789854

Change-Id: I2ce6141c55fe874ab11f9f236b4734b9a9d79617
Reviewed-on: https://chromium-review.googlesource.com/1192360
Commit-Queue: Han Leon <leon.han@intel.com>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587362}
23 files changed