What's new in the WebKitGTK 2.53.1 release?
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  - Remove the option to use cairo for 2D rendering.
  - Implement GPU atlas creation and replay substitution for batched raster image uploads.
  - Improved non accelerated composited mode by using the same buffer sharing
    implementation as accelerated mode.
  - The on-demand hardware acceleration policy is now deprecated in GTK3 API.
  - Add new improved API for page favicons.
  - Add webkit_feature_list_find() to public API.
  - Support PGO features in regular CMake builds.
  - Fix several crashes and rendering issues.