Use Skia integer primitives for drawing Chromium Linux scrollbars

[Adam Langley]

The Skia drawLine function takes subpixel values and attempts to draw
a line with subpixel precision. This is complex and slow for drawing
scrollbars which use only vertical and horizontal lines.

This changes the Chromium Linux scrollbar code to use drawIRect.

Layout test changes will be in the Chromium tree.

[Adam Langley]

Created attachment 28737 [details]
patch

[Darin Fisher (:fishd, Google)]

Comment on attachment 28737 [details]
patch

> +static void drawVertLine(SkCanvas* canvas, int x, int y1, int y2, const SkPaint& paint) {
> +  SkIRect skrect;
> +  skrect.set(x, y1, x + 1, y2 + 1);
> +  canvas->drawIRect(skrect, paint);
> +}

nit: please use webkit style (4 space indent, bracket on newline).  there are a lot of
these style violations in this patch as well as in the previous file.  please fix :)

[Adam Langley]

Created attachment 28917 [details]
patch

[Darin Fisher (:fishd, Google)]

Landed as:  http://trac.webkit.org/changeset/41960