tree f4ac60fc18db85370d93f51c7cc38ae853be4c2f
parent 5e38ff21ba3b3823dd7d2f45ee7ab0b3fa53f1ae
author Xianzhu Wang <wangxianzhu@chromium.org> 1570052617 +0000
committer Commit Bot <commit-bot@chromium.org> 1570052617 +0000

Refactor cc painted scrollbar

- Remove unused cc/layers/scrollbar_theme_painter.h
- Add comments in cc::Scrollbar
- Remove rect parameter from cc::Scrollbar::PaintPart() because the
  rect can be easily calculated by blink, given that the coordinate
  space of the canvas is clearly defined
- Improve performance of blink::ScrollbarLayerDelegate::HasTickMarks
  (implementation of cc::Scrollbar::HasTickMarks()). The old
  implementation queried all tick marks and see if it was empty, which
  may be slow when there are a lot of tick marks (e.g. when searching
  in a huge document).
- Add blink::ScrollbarTheme::PaintTrackAndButtonsForCompositor() to
  avoid exposing too much details of ScrollbarTheme to outside.

This is a preparation for CompositeAfterPaint composited scrollbar
implementation.

Change-Id: Ibf8c7a90d80ddf972f215495d0fd89470fa2deb4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1834286
Reviewed-by: Philip Rogers <pdr@chromium.org>
Commit-Queue: Xianzhu Wang <wangxianzhu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#702201}