Add animatable flag to CSSProperties.in

Add animatable flag to CSSProperties.in

This patch adds the flag 'animatable' to CSSProperties.in, replacing the
existing switch statement in CSSAnimations.cpp. Setting the flag
indicates that the property can be animated by CSS animations and
transitions.

The added code will generate a function in CSSPropertyMetadata, which
will eventually also support functions like isInheritedProperty and
isValidFirstLetterStyleProperty. This means that the individual lines in
CSSProperties.in may start getting a bit long, although a centralized
specification of our supported CSS properties arguably helps developers
add new CSS properties, by reducing the lines they need to add and
adding documentation on what changes need to be made.

BUG=396992
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180039

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=180213

[Timothy Loh, 2014-08-12 01:53:12]

(depends on https://codereview.chromium.org/415613002/ landing first, although
it's already in the cq)

[alancutter (OOO until 2018), 2014-08-12 03:18:27]

lgtm

[Timothy Loh, 2014-08-12 06:19:11]

The CQ bit was checked by timloh@chromium.org

[commit-bot: I haz the power, 2014-08-12 06:19:29]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/timloh@chromium.org/454423003/20001

[commit-bot: I haz the power, 2014-08-12 07:24:44]

Change committed as 180039

[adamk, 2014-08-12 18:17:28]

Reverted in https://src.chromium.org/viewvc/blink?revision=180090&view=revision
for assertion failures in print preview browser_tests

[Timothy Loh, 2014-08-13 23:57:36]

The CQ bit was checked by timloh@chromium.org

[commit-bot: I haz the power, 2014-08-13 23:58:11]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/timloh@chromium.org/454423003/20001

[commit-bot: I haz the power, 2014-08-13 23:58:55]

Committed patchset #2 (20001) as 180213