Reapply r168568 "Remove unneeded destructors and add finalization support to various classes."

Reapply r168568 "Remove unneeded destructors and add finalization support to various classes."

The previous CL (https://codereview.chromium.org/184853006) caused a clang crash (http://llvm.org/bugs/show_bug.cgi?id=16220).
The issue is resolved by placing the implementation of the pure-virtual destructor in the header file.
This CL also makes the destructor non-pure because the CSSCalcExpressionNode has other pure-virtuals.

R=haraken@chromium.org
BUG=

[haraken, 2014-03-06 10:52:12]

LGTM

[zerny-chromium, 2014-03-06 11:19:36]

The CQ bit was checked by zerny@chromium.org

[commit-bot: I haz the power, 2014-03-06 11:19:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zerny@chromium.org/188473004/1

[commit-bot: I haz the power, 2014-03-06 11:21:16]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-06 11:21:16]

Try jobs failed on following builders: mac_blink_rel

[zerny-chromium, 2014-03-06 11:32:28]

The CQ bit was checked by zerny@chromium.org

[commit-bot: I haz the power, 2014-03-06 11:32:40]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zerny@chromium.org/188473004/1

[commit-bot: I haz the power, 2014-03-06 12:17:17]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-06 12:17:17]

Try jobs failed on following builders: linux_blink

[zerny-chromium, 2014-03-06 13:19:29]

The CQ bit was checked by zerny@chromium.org

[commit-bot: I haz the power, 2014-03-06 13:19:34]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zerny@chromium.org/188473004/1

[commit-bot: I haz the power, 2014-03-06 13:38:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-06 13:38:52]

Try jobs failed on following builders: linux_blink

[zerny-chromium, 2014-03-06 15:04:06]

The CQ bit was checked by zerny@chromium.org

[commit-bot: I haz the power, 2014-03-06 15:04:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zerny@chromium.org/188473004/1

[commit-bot: I haz the power, 2014-03-06 15:08:18]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-06 15:08:19]

Try jobs failed on following builders: linux_blink

[zerny-chromium, 2014-03-07 07:00:59]

The CQ bit was checked by zerny@chromium.org

[commit-bot: I haz the power, 2014-03-07 07:01:16]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/zerny@chromium.org/188473004/20001

[commit-bot: I haz the power, 2014-03-07 07:45:39]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-03-07 07:45:39]

Try jobs failed on following builders: win_blink_rel

[zerny-chromium, 2014-03-11 11:42:18]

I'm going to abandon this change and merge it into
https://codereview.chromium.org/189543014/