Remove old VS2010 toolchain script

VS2010 no longer supported, and the 2013 toolchain code was rolled into
depot_tools. Remove this outdated script.

TBR=cpu@chromium.org
BUG=309197

Review URL: https://codereview.chromium.org/195873007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256675 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256675