Goal is to encourage callers to handle errors, especially in cases
like schema changes, where dropped errors can result in broken
databases.
Many CREATE INDEX calls where ignoring errors rather than checking if
the index already existed before creating it. Recoded those to CREATE
INDEX IF NOT EXISTS, which is for exactly this purpose.
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/9005036
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@115725 0039d316-1c4b-4281-b951-d872f2087c98