Trivial cleanups to SQLValue.h

- do not indent code inside namespace
- remove unnecessary include

just two things I noticed while I looked at this file.

BUG=None
TEST=none, no behavior changes
R=michaeln@chromium.org

Review URL: https://codereview.chromium.org/50143003

git-svn-id: svn://svn.chromium.org/blink/trunk@160855 bbb929c8-8fbe-4397-9dbb-9b2b20218538