Cookies Tree: Reduce header size, merge declarations/definitions

* Move definitions of various internal CookieTreeXXXNode types
   from .h into .cc
* IWYU fixes
* Remove redundant StorageUsageInfo members in DetailedInfo
* Make a dummy callback a OnceClosure to satisfy presubmit

No functional changes.

Change-Id: I6d338e7baa5cc4b9571765b88480208a1b301743
Commit-Queue: Joshua Bell <>
Reviewed-by: Steven Bennetts <>
Reviewed-by: Christian Dullweber <>
Cr-Commit-Position: refs/heads/master@{#623762}
4 files changed