[webkit-changes] [WebKit/WebKit] 1b57a2: [UI-side compositing] NSScrollerImps are still cre...

[Nikos Mouchtaris]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 1b57a2e0de6aad8821281cd336b13ab56f57d19e
      https://github.com/WebKit/WebKit/commit/1b57a2e0de6aad8821281cd336b13ab56f57d19e
  Author: Nikolaos Mouchtaris <nmouchtaris at apple.com>
  Date:   2023-07-03 (Mon, 03 Jul 2023)

  Changed paths:
    M Source/WebCore/platform/Scrollbar.cpp
    M Source/WebCore/platform/Scrollbar.h
    M Source/WebCore/platform/ScrollbarsController.h
    M Source/WebCore/platform/mac/ScrollbarThemeMac.mm
    M Source/WebKit/WebProcess/WebPage/RemoteLayerTree/RemoteScrollbarsController.h

  Log Message:
  -----------
  [UI-side compositing] NSScrollerImps are still created in the web process (triggering CATransactions)
https://bugs.webkit.org/show_bug.cgi?id=258369
rdar://109689491

Reviewed by Simon Fraser.

With UI-side compositing, NSScrollerImps are now kept in the UI-process for all scrollbars
except for RenderListBox scrollbars. To prevent the unnecessary creation of NSScrollerImps
in the web process in ScrollbarThemeMac::registerScrollbar, check if the scrollbar is one
of a RenderListBox and if we have a RemoteScrollbarsController.

* Source/WebCore/platform/ScrollableArea.cpp:
(WebCore::ScrollableArea::shouldRegisterScrollbars const):
* Source/WebCore/platform/ScrollableArea.h:
* Source/WebCore/platform/Scrollbar.cpp:
(WebCore::Scrollbar::shouldRegisterScrollbar const):
* Source/WebCore/platform/Scrollbar.h:
* Source/WebCore/platform/ScrollbarsController.h:
(WebCore::ScrollbarsController::shouldRegisterScrollbars const):
* Source/WebCore/platform/mac/ScrollbarThemeMac.mm:
(WebCore::ScrollbarThemeMac::registerScrollbar):
* Source/WebKit/WebProcess/WebPage/RemoteLayerTree/RemoteScrollbarsController.h:

Canonical link: https://commits.webkit.org/265731@main