Refactors FileSystemQuotaClient using base::Callback.

BUG=139270


Review URL: https://chromiumcodereview.appspot.com/10828177

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150290 0039d316-1c4b-4281-b951-d872f2087c98
2 files changed