Allow CookieManager to be used without starting Chromium.

Refactor the CookieManager to allow it to be used without starting
Chromium. If Chromium has not been started when the cookie manager is
first used, a temporary cookie monster will be created and used to
service requests (with its own client/backend threads). If the app
subsequently triggers regular Chromium startup (e.g. by creating a
WebView) then the temporary one will be shut down cleanly before the
real instance is created.

Bug: 10969703
Change-Id: I903630cbdbccc61958e5e8b9179c0a3d09594a8b
13 files changed