Simplify FakeGaiaCookieManagerService

Simplifying the FakeGaiaCookieManagerService API by not requiring to
call Init() with a FakeURLFetcherFactory. The FakeURLFetcherFactory is
instead a member of the FakeGaiaCookieManagerService.

This API simplification is in preparation for switching GaiaAuthFetcher
to use the SimpleURLLoader (network service).

Bug: 840396
Change-Id: I917e4236a53bf251c3a8e82c868d5e4d99655aca
Reviewed-on: https://chromium-review.googlesource.com/1114226
Reviewed-by: Avi Drissman <avi@chromium.org>
Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: Jay Civelli <jcivelli@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574588}
15 files changed