[Drive] Rename DriveServiceInterface::DeleteResource to TrashResource

Rename the method name to proper one as a preparation to adding real DeleteResource.

BUG=240165
NOTRY=true
R=hashimoto@chromium.org, nhiroki@chromium.org

Review URL: https://codereview.chromium.org/103033006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240275 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240275