Move GetFetchClientSettingsObject() to FetchContext

As preparation for plumbing FetchClientSettingsObject via
FetchContext rather than as an argument,
this CL exposes GetFetchClientSettingsObject() in FetchContext.

NullFetchContext is added just to make
FetchContext::GetFetchClientSettingsObject() abstract and
FetchContext::NullInstance()'s GetFetchClientSettingsObject()

This CL doesn't change the behavior.

Bug: 880027
Change-Id: I02a428d77d202ab88cffd22a3fdf3cd34eff4aca
Reviewed-by: Yutaka Hirano <>
Reviewed-by: Hiroki Nakagawa <>
Commit-Queue: Hiroshige Hayashizaki <>
Cr-Commit-Position: refs/heads/master@{#606759}
4 files changed