ServiceWorker: Consolidate version change messages

This consolidates IPC messages for setting up version attributes
(ie. installing, waiting and active), and cleans up related functions.

The new message is intended to be used for ServiceWorkerRegistration
object that will be introduced by following CL[1] and it doesn't have
the controller field, so the controller still use a separate message.


TEST=content_unittests --gtest_filter=ServiceWorker* --debug http/tests/serviceworker

Review URL:

Cr-Commit-Position: refs/heads/master@{#289240}
git-svn-id: svn:// 0039d316-1c4b-4281-b951-d872f2087c98
10 files changed