Make font-weight animatable.

Make font-weight animatable.

We currently don't animate font-weight, even though (1) the spec calls for it, and (2) other
browsers (IE+FF) do.

The interpolator converts the font weights to equivalent real numbers, and performs
the interpolation on these values. The font weight is rounded to the nearest 100 when
the animated style is built.

BUG=289734
TEST=automated

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=167784

[alancutter (OOO until 2018), 2014-02-21 00:24:25]

Thanks again for the patch, it's appreciated!

As mentioned on IRC the AnimatableFontWeight class is probably unnecessary. The
conversion between FontWeight and double should occur in the factory and builder
while the interpolation/addition logic itself is handled by AnimatableDouble.

[leviw_travelin_and_unemployed, 2014-02-21 00:54:17]

The RenderStyle changes lgtm, but I defer to AlanCutter for the Animation stuff.

[andersr, 2014-02-21 11:42:41]

AnimatableFontWeight removed. PTAL (alancutter).

[alancutter (OOO until 2018), 2014-02-23 23:01:07]

lgtm with nits.

https://codereview.chromium.org/173953002/diff/60001/LayoutTests/animations/i...
File LayoutTests/animations/interpolation/font-weight-interpolation.html
(right):

https://codereview.chromium.org/173953002/diff/60001/LayoutTests/animations/i...
LayoutTests/animations/interpolation/font-weight-interpolation.html:76: {at:
8/8, is: '900'},
Since this property is bounded between 100 and 900 we should also test
interpolation values outside the range 0 to 1.

https://codereview.chromium.org/173953002/diff/60001/Source/core/css/resolver...
File Source/core/css/resolver/AnimatedStyleBuilder.cpp (right):

https://codereview.chromium.org/173953002/diff/60001/Source/core/css/resolver...
Source/core/css/resolver/AnimatedStyleBuilder.cpp:232: if (index < 0 || index >
8)
Better to use WTF_ARRAY_LENGTH(weights) here instead of a hard coded number.

https://codereview.chromium.org/173953002/diff/60001/Source/core/css/resolver...
Source/core/css/resolver/AnimatedStyleBuilder.cpp:235: static const FontWeight
weights[9] = {
No need to declare array size.

[alancutter (OOO until 2018), 2014-02-24 23:01:04]

lgtm behaviour change with nit.

https://codereview.chromium.org/173953002/diff/170001/Source/core/css/resolve...
File Source/core/css/resolver/AnimatedStyleBuilder.cpp (right):

https://codereview.chromium.org/173953002/diff/170001/Source/core/css/resolve...
Source/core/css/resolver/AnimatedStyleBuilder.cpp:244: index =
std::min(std::max(index, 0), static_cast<int>(WTF_ARRAY_LENGTH(weights)) - 1);
clampTo<int>()

[andersr, 2014-02-25 09:26:38]

The CQ bit was checked by andersr@opera.com

[commit-bot: I haz the power, 2014-02-25 09:26:45]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/andersr@opera.com/173953002/210001

[commit-bot: I haz the power, 2014-02-25 13:29:12]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/andersr@opera.com/173953002/210001

[commit-bot: I haz the power, 2014-02-25 15:21:31]

Change committed as 167784