[webkit-changes] [WebKit/WebKit] 9d7f3d: Web font creation data isn't attributed to the Web...

[mattwoodrow]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 9d7f3dc4ca95b3f2b790bc43f8603f153225bab6
      https://github.com/WebKit/WebKit/commit/9d7f3dc4ca95b3f2b790bc43f8603f153225bab6
  Author: Matt Woodrow <mattwoodrow at apple.com>
  Date:   2023-01-11 (Wed, 11 Jan 2023)

  Changed paths:
    M Source/WebKit/Shared/Cocoa/WebCoreArgumentCodersCocoa.mm

  Log Message:
  -----------
  Web font creation data isn't attributed to the WebContent process and can cause jetsams in the GPUP.
https://bugs.webkit.org/show_bug.cgi?id=250469
<rdar://100866403>

Reviewed by Dean Jackson.

We're currently copying Font creationData across IPC using shmem (as part of the FragmentedSharedBuffer serialisation), but we then copy it back into local memory.
This adds an extra copy, but also means we can't attribute the memory to the WebContent process that owns the Font.

This change adds the shmem copy into the Font serialization code, and retains the shmem to back the font data in the GPUP.

* Source/WebKit/Shared/Cocoa/WebCoreArgumentCodersCocoa.mm:
(IPC::ArgumentCoder<WebCore::Font>::encodePlatformData):
(IPC::ArgumentCoder<WebCore::Font>::decodePlatformData):

Canonical link: https://commits.webkit.org/258817@main