Electron Releases

Description of Change

DraggableRegionsToSkRegion (browser UI thread, run on every DraggableRegionsChanged from the renderer) applied each rect with its own SkRegion::op(). Each op is linear in the region built so far, so N non‑adjacent app-region rects cost O(N²): a page with a few thousand draggable tiles stalls the whole app for 100 ms–seconds every time layout moves them.

• Union each run of consecutive same‑kind rects with SkRegion::setRects() (divide‑and‑conquer) and fold the runs in document order. Later rects still win over earlier ones, so the result is identical to before; checked against the old loop on 20k randomized inputs (mixed drag/no‑drag order, empty and negative rects) with zero differences.
• Release‑Skia timings for one update, disjoint 18×18 tiles / one drag rect with N‑1 no‑drag holes:

• End to end (frameless window, 40 layouts that each shift 10k regions): main‑process max stall 2.6 s → no gap over 9 ms. Heavily interleaved drag/no‑drag sequences fall back toward the old cost since order has to be preserved, but never worse than before.

Checklist

• PR description included
• npm test passes

Release Notes

Notes: Fixed the app becoming unresponsive when a page has a very large number of app-region draggable elements.