win: Remove msbuild_toolset, and msvs-specific ProgramDatabaseFile.

Since we're now on ninja, they don't have an effect.

BUG=none
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/145493007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@246783 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 246783