Update some uses of Value in chrome/browser to use the base:: namespace.

BUG=88666
TEST=no change
R=brettw@chromium.org
TBR=ben@chromium.org

Review URL: https://codereview.chromium.org/106433007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242387 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242387