[css3-text] Add platform support for "wavy" text decoration style
https://bugs.webkit.org/show_bug.cgi?id=92868

Patch by Lamarque V. Souza <Lamarque.Souza@basyskom.com> on 2013-03-28
Reviewed by Benjamin Poulain.

Source/WebCore:

This patch uses GraphicsContext::strokePath() to implement
wavy decoration for the CSS3 property "text-decoration-style".

No new tests as this is covered with existing tests.

* rendering/InlineTextBox.cpp:
(WebCore::textDecorationStyleToStrokeStyle): Remove obsolete comment.
(WebCore::adjustStepToDecorationLength): Add function to adjust
variables used to calculate the lenght of Bezier curves.
(WebCore::strokeWavyTextDecoration): Add function to stroke wavy
decoration based on cubic Bezier curve.
(WebCore::InlineTextBox::paintDecoration): Call
strokeWavyTextDecoration when necessary.

LayoutTests:

Rebaseline chromium-linux expectation for
fast/css3-text/css3-text-decoration/text-decoration-style.html.

* platform/chromium-linux/fast/css3-text/css3-text-decoration/text-decoration-style-expected.png: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147170 268f45cc-cd09-0410-ab3c-d52691b4dbfc