drive: Drop WAPI support code from CopyOperation

BUG=324382
TEST=unit_tests
R=kinaba@chromium.org

Review URL: https://codereview.chromium.org/108233006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240056 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240056