Clamp wordSpacing percentage value.
https://bugs.webkit.org/show_bug.cgi?id=129350.

Patch by Said Abou-Hallawa <sabouhallawa@apple.com> on 2014-10-24
Reviewed by Zalan Bujtas.

Source/WebCore:

When the CSS wordSpacing property is percentage, its value has to be within the
pre-defined min/max values for the CSS length type. This is done the same way
the wordSpacing of type <length> is handled.

Tests: css3/infinite-word-spacing.html.

Move the definitions of minValueForCssLength and maxValueForCssLength from the
.cpp file to the .h file.
* css/CSSPrimitiveValue.cpp:
* css/CSSPrimitiveValue.h:

Clamp the wordSpacing value to minValueForCssLength and maxValueForCssLength when
its type is percentage.
* css/DeprecatedStyleBuilder.cpp:
(WebCore::ApplyPropertyWordSpacing::applyValue):

LayoutTests:

Make sure that setting the CSS style wordSpacing property to very huge percentage
value and blending this value with other values for animating key frames does
not assert or crash. The expectation is to have this huge value to be clamped to
the pre-defined min/max values for the CSS length type. So when blending the clamped
value with other wordSpacing values, the result can't be NaN. This should be very
similar to the case when it is set to a huge <length> value.

* css3/infinite-word-spacing-expected.txt: Added.
* css3/infinite-word-spacing.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@175197 268f45cc-cd09-0410-ab3c-d52691b4dbfc