commit 37855993b8455236d35a391cb0c1f2fa33c44b88
author Gastón Rodríguez <gastonr@microsoft.com> Thu Nov 21 00:09:44 2024
committer Chromium LUCI CQ <chromium-scoped@luci-project-accounts.iam.gserviceaccount.com> Thu Nov 21 00:09:44 2024
tree 1b511955bf1c0d841e3371a13cbefb00eb2d9627
parent 8a1365beabbfb3f7070778782188e49a75993026

Fix scaling for 9-patch scrollbars.

When pinch-zooming in a subscroller that is being rendered with nine-
patch scrolling the track shows strange behavior. In official builds
the rendering of the thumb and arrows gets distorted and in local
builds it is clear that the scrollbar's track and buttons are not
being scaled.

The root causes for this bug were:
1. The patch generator was not being passed the scaled rect by the layer
   code, it was only being given the layer's dimensions.
2. The track's bitmap wasn't being repainted when scaled, which in the
   best case scenario caused the arrows to look blurry, and in the worst
   it caused the rendering to be completely wrong.
3. The aperture wasn't being scaled to consider the bitmap's scaled
   dimensions, which caused scaled scrollbars to be rendered
   incorrectly.

This CL:
1. Adds a new condition for the scrollbars to be re-painted whenever the
   layer's internal scale changes.
2. Refactors the ScrollbarTheme 9patch-Canvas and 9patch-Aperture code
   to consider the scale of the layer and return the correct sized
   values.
3. Adds web and unittests to cover the new behavior.

Bug: 378027651
Change-Id: Ie467ecc8139e2a6b03d5d073ac2c860bf2cd571d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6013524
Commit-Queue: Gaston Rodriguez <gastonr@microsoft.com>
Reviewed-by: Xianzhu Wang <wangxianzhu@chromium.org>
Reviewed-by: Yaroslav Shalivskyy <yshalivskyy@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1385971}