Rename/modify test case for explicitly set caret type

This test has nothing to do with user-select: none. Hence renaming
the test case.
This test was created as part of https://codereview.chromium.org/23461040/

Review URL: https://chromiumcodereview.appspot.com/23464103

git-svn-id: svn://svn.chromium.org/blink/trunk@158085 bbb929c8-8fbe-4397-9dbb-9b2b20218538