[webkit-changes] [WebKit/WebKit] 42fe4a: Disable GlyphDisplayListCache on watchOS

[Cameron McCormack]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 42fe4a9f7ac5d2ecb5bd81e40ff9524f445e22ef
      https://github.com/WebKit/WebKit/commit/42fe4a9f7ac5d2ecb5bd81e40ff9524f445e22ef
  Author: Cameron McCormack <heycam at apple.com>
  Date:   2022-09-09 (Fri, 09 Sep 2022)

  Changed paths:
    M Source/WTF/wtf/PlatformUse.h
    M Source/WebCore/rendering/TextPainter.cpp

  Log Message:
  -----------
  Disable GlyphDisplayListCache on watchOS
https://bugs.webkit.org/show_bug.cgi?id=245005
rdar://97623892

Reviewed by Myles Maxfield.

The GlyphDisplayListCache has two purposes:

1. To reduce the amount of glyph vector data being transferred from the
   Web process to the GPU process when drawing frequently repainted
   text.
2. To cache the results of text shaping so that frequently repainted
   text can be drawn faster (primarily to help with benchmarks).

On watchOS, we don't have the GPU process enabled, and we also don't
particularly care about MotionMark scores on Watch. To avoid some OOM
situations that are occurring due to the GlyphDisplayListCache, this
disables the cache on watchOS.

* Source/WTF/wtf/PlatformUse.h:
* Source/WebCore/rendering/TextPainter.cpp:
(WebCore::TextPainter::shouldUseGlyphDisplayList):

Canonical link: https://commits.webkit.org/254347@main