)]}'
{
  "commit": "7152f2b3147f224f819d17d4301c21517c0a176b",
  "tree": "dfbab2d404feb986e7c25dd3bc975a4eed3d171f",
  "parents": [
    "3c5c58d1cfd5304cc247ee7045bf0841706e782e"
  ],
  "author": {
    "name": "zhongliugo",
    "email": "zhongliu88889@gmail.com",
    "time": "Thu Jul 09 09:56:37 2026 -0700"
  },
  "committer": {
    "name": "GitHub",
    "email": "noreply@github.com",
    "time": "Thu Jul 09 16:56:37 2026 +0000"
  },
  "message": "[web] Avoid absolute positioning for base CanvasKit canvas (#188337)\n\nfix for #176327\nPartial fix for #181511\n\n**Problem**\n\nWith CanvasKit and semantics enabled, scrolling regular Flutter Web\ncontent on iPhone WebKit browsers can be very janky. The base CanvasKit\ncanvas was always styled with `position:absolute`, which is expensive\nfor WebKit to scroll together with the semantics DOM.\n\n**Fix**\n\nOnly platform-view overlay canvases keep `position:absolute`. The normal\nbase CanvasKit canvas now uses regular positioning, which fixes the\nplain Flutter scroll case while preserving `HtmlElementView` stacking.\n\nOne limitation: mixed Flutter and `HtmlElementView` scenes may still\nshow iOS WebKit scroll jank because platform-view overlays still require\n`position:absolute`.\n\n**Demo**\n\n| Before | After |\n|---|---|\n| https://flutter-demo-09-before.web.app |\nhttps://flutter-demo-09-after.web.app |\n\nSteps: open the page on iPhone Chrome or Safari, keep semantics enabled,\nthen scroll the page continuously.\n\nBefore: the on-screen jank log shows severe scroll jank, including runs\nover 100 janky frames per 5 seconds.\n\nAfter: the same regular Flutter content stays smooth, with low jank\nsummaries around 1 to 10 janky frames per 5 seconds in validation runs.",
  "tree_diff": [
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}