add features for border-style dashed, dotted, double.

[flyskyko]

Summary

This PR fixes/implements the following bugs/features

• Fixes incorrect rounded border box
• Dashed border style
• Dotted border style
• Double border style

• Fixes incorrect rounded border box
  • Change parameter value of XxxXxxPaddingBox correctly in bound-curves.ts
• Dashed border style
  • Calculate a dash length and space length (I referred to the Chromium source code)
  • Draw dash line on border outer path with double thickness and clip
  • If corner is rounded draw additional line to fill the gaps between the sides.
• Dotted border style
  • Added XxxXxxBorderStroke in bound-curves.ts
  • Calculate a dash length and space length (I referred to the Chromium source code)
  • Draw dash line with round line cap on border center path
• Double border style
  • Added XxxXxxBorderDoubleOuterBox and XxxXxxBorderDoubleInnerBox
  • Fill outer box and inner box

Test plan (required)

Dashed (browser, tests/reftests/border/dashed.html)

Dashed (html2canvas, tests/reftests/border/dashed.html)

Dotted (browser, tests/reftests/border/dotted.html)

Dotted (html2canvas, tests/reftests/border/dotted.html)

Double (browser, tests/reftests/border/double.html)

Double (html2canvas, tests/reftests/border/double.html)

Radius (browser, tests/reftests/border/radius.html)

Radius (html2canvas this branch, tests/reftests/border/radius.html)

Radius (html2canvas 1.0.0-rc.7, tests/reftests/border/radius.html)

Closing issues

Fixes #210, Fixes #366, Fixes #1354

[margox]

@flyskyko Good job!
and will this feature be released in the next version? @mephju

[mephju]

oh i don't run this project. i just approved it. honestly tho this project seems to be abandoned.