Pass the selection text into Pasteboard from the Editor.

Also remove the ShouldSerializeSelectedTextForClipboard enum, as only
one of its enumerators ever applies.

BUG=276565

Review URL: https://chromiumcodereview.appspot.com/23242013

git-svn-id: svn://svn.chromium.org/blink/trunk@156569 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a virtual test suite for exposed "stable" features

This change removes enabling all the runtime enabled features in
TestInterfaces. This code gone, we can use the new stable flag
to add a test suite for "stable" features only (yay!).

BUG=234853

Review URL: https://chromiumcodereview.appspot.com/22897010

git-svn-id: svn://svn.chromium.org/blink/trunk@156570 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Support 'paint-order' from SVG2.

R=pdr@chromium.org
BUG=223766

Review URL: https://codereview.chromium.org/14907011

Patch from Erik Dahlström <ed@opera.com>.

git-svn-id: svn://svn.chromium.org/blink/trunk@156571 bbb929c8-8fbe-4397-9dbb-9b2b20218538