[webkit-changes] [WebKit/WebKit] aaf9fe: WebGLExtensionBase's derived classes are wrongly d...

[Yusuke Suzuki]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: aaf9fecff4bd3457d17e16e5dd61afdbd2ca6ba6
      https://github.com/WebKit/WebKit/commit/aaf9fecff4bd3457d17e16e5dd61afdbd2ca6ba6
  Author: Yusuke Suzuki <ysuzuki at apple.com>
  Date:   2024-02-06 (Tue, 06 Feb 2024)

  Changed paths:
    M Source/WebCore/html/canvas/WebGLExtension.h
    M Source/WebCore/platform/animation/AcceleratedEffectStack.h

  Log Message:
  -----------
  WebGLExtensionBase's derived classes are wrongly deleted
https://bugs.webkit.org/show_bug.cgi?id=268868
rdar://121954439

Reviewed by Mark Lam.

While WebGLExtensionBase has RefCounted<WebGLExtensionBase> and it has many derived classes, it does not have virtual destructor.
This is completely wrong since Ref<DerivedClass> will only invoke ~WebGLExtensionBase() since RefCounted<WebGLExtensionBase>::deref() can only invoke it.
This is totally breaking IsoHeap since we need to call and dispatch derived classes' delete / destructor, but now it is not.
As a result, we are observing IsoHeap related crashes with this. This adds virtual destructor for WebGLExtensionBase.

Also RemoteAcceleratedEffectStack has the exact same bug too. This patch also fixes it.

* Source/WebCore/html/canvas/WebGLExtension.h:

Canonical link: https://commits.webkit.org/274198@main