Write a public ServiceWorker API.
Add a test and fix a bug.
Fix two compilations
Fix gypi files
Fix #include guard name.
Fix kinuko's comments.
Merge branch 'public-sw-api' into service-worker-apps

Conflicts:
	content/browser/service_worker/service_worker_context_wrapper.cc
	content/browser/service_worker/service_worker_context_wrapper.h
	content/public/browser/service_worker_context.h