Remove Explicit Shapes Enablement in Tests

Shapes are enabled by default when running tests, so the calls to internal settings can be removed.

BUG=248304

Review URL: https://chromiumcodereview.appspot.com/20806004

git-svn-id: svn://svn.chromium.org/blink/trunk@156108 bbb929c8-8fbe-4397-9dbb-9b2b20218538