[Sync] Put everything in sync/api into csync namespace

BUG=128060
TEST=
TBR=pkasting@chromium.org

Review URL: https://chromiumcodereview.appspot.com/10662035

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@144385 0039d316-1c4b-4281-b951-d872f2087c98
139 files changed