Mojo: Improve comments in core.h.

TBR=darin@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/157813012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250716 0039d316-1c4b-4281-b951-d872f2087c98
Keep reconcilor for looping when cookies change.

Changes:
- only listen for cookie changes when connected
- delay the end of the reconcile action until merge sessions are complete
- if /ListAccounts returns an error, just abort the reconcile
- change DVLOG to VLOG so we can turn on logging in canary

BUG=340775

Review URL: https://codereview.chromium.org/152633007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250717 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250717