DirectoryContents should be responsible just for fetching entries.
This CL removes the createDirectory method from DirectoryContents.

BUG=none
TEST=manually

Review URL: https://codereview.chromium.org/150263002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248195 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@248196 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 248196