Add Service Worker Events to EventType.
Add Service Worker Events to EventType.

https://w3c.github.io/ServiceWorker/#execution-context-events
https://w3c.github.io/ServiceWorker/#document-context-events

RELNOTES:goog.events.EventType is updated with Service Worker events.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=155614611

teppeis/closure-library,platinumpixs/google-closure-library,lucidsoftware/closure-library,google/closure-library,teppeis/closure-library,lucidsoftware/closure-library,google/closure-library,platinumpixs/google-closure-library,platinumpixs/google-closure-library,google/closure-library,google/closure-library,teppeis/closure-library,lucidsoftware/closure-library,teppeis/closure-library,platinumpixs/google-closure-library,lucidsoftware/closure-library,google/closure-library