Remove number conversion functions from string_util. These moved to string_number_conversions.

TEST=it compiles
BUG=none
Review URL: http://codereview.chromium.org/3054036

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@54747 0039d316-1c4b-4281-b951-d872f2087c98
23 files changed