[webkit-changes] [WebKit/WebKit] fe2cfb: [iOS] Memory management of WebAVPictureInPicturePl...

[aestes]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: fe2cfbc719090ccedd59a6286cd3523ab7bf5cd3
      https://github.com/WebKit/WebKit/commit/fe2cfbc719090ccedd59a6286cd3523ab7bf5cd3
  Author: Andy Estes <aestes at apple.com>
  Date:   2023-10-30 (Mon, 30 Oct 2023)

  Changed paths:
    M Source/WebCore/platform/cocoa/WebAVPlayerLayerView.mm

  Log Message:
  -----------
  [iOS] Memory management of WebAVPictureInPicturePlayerLayerView instances in WebAVPlayerLayerView is confusing
https://bugs.webkit.org/show_bug.cgi?id=263916
rdar://117364434

Reviewed by Tim Horton and Simon Fraser.

WebAVPlayerLayerView_pictureInPicturePlayerLayerView creates an instance of
WebAVPictureInPicturePlayerLayerView but does not adopt it, leaking its +1 retain count. It is then
stored in WebAVPlayerLayerView's _pictureInPicturePlayerLayerView ivar, which retains it. Later,
WebAVPlayerLayerView_dealloc adopts the leaked instance stored in _pictureInPicturePlayerLayerView
and sets the ivar to nil. This releases the instance twice, balancing the +2 retain count from
earlier. This is correct but confusing, as it isn't the conventional way we manage an instance's
retain count.

Addressed the confusion by adopting the new WebAVPictureInPicturePlayerLayerView instance in
WebAVPlayerLayerView_pictureInPicturePlayerLayerView rather than leaking it until
WebAVPlayerLayerView_dealloc is called. Fixed a few formatting issues while here.

* Source/WebCore/platform/cocoa/WebAVPlayerLayerView.mm:
(WebCore::WebAVPlayerLayerView_setPlayerController):
(WebCore::WebAVPlayerLayerView_playerLayer):
(WebCore::WebAVPlayerLayerView_startRoutingVideoToPictureInPicturePlayerLayerView):
(WebCore::WebAVPlayerLayerView_pictureInPicturePlayerLayerView):
(WebCore::WebAVPlayerLayerView_dealloc):
(WebCore::allocWebAVPlayerLayerViewInstance):
(WebCore::allocWebAVPictureInPicturePlayerLayerViewInstance):

Canonical link: https://commits.webkit.org/269989@main