Fix templating library to not strip newlines at the end of files

Also trim the templates that previously had an extra newline at the end.

BUG=290204

Review URL: https://chromiumcodereview.appspot.com/23460035

git-svn-id: svn://svn.chromium.org/blink/trunk@157712 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove some uncalled method from Theme / ScrollbarTheme

Theme::defaultStyleSheet was also not implemented.

Review URL: https://chromiumcodereview.appspot.com/23620041

git-svn-id: svn://svn.chromium.org/blink/trunk@157713 bbb929c8-8fbe-4397-9dbb-9b2b20218538