drive: Overwrite existing file with TransferFileFromLocalToRemote

BUG=340607
TEST=unit_tests

Review URL: https://codereview.chromium.org/145723006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@249023 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 249023