[webkit-changes] [WebKit/WebKit] 7b312e: AX: Avoid hitting the main thread to retrieve posi...

[AndresGonzalezApple]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 7b312e8e9f18faa378255c49f3ab63c3ff2ea057
      https://github.com/WebKit/WebKit/commit/7b312e8e9f18faa378255c49f3ab63c3ff2ea057
  Author: Andres Gonzalez <andresg_22 at apple.com>
  Date:   2023-05-02 (Tue, 02 May 2023)

  Changed paths:
    M Source/WebCore/loader/EmptyClients.cpp
    M Source/WebCore/loader/EmptyFrameLoaderClient.h
    M Source/WebCore/loader/FrameLoaderClient.h
    M Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.cpp
    M Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.h
    M Source/WebKit/WebProcess/WebPage/WebPage.cpp
    M Source/WebKit/WebProcess/WebPage/WebPage.h
    M Source/WebKit/WebProcess/WebPage/mac/WKAccessibilityWebPageObjectBase.h
    M Source/WebKit/WebProcess/WebPage/mac/WKAccessibilityWebPageObjectBase.mm
    M Source/WebKit/WebProcess/WebPage/mac/WKAccessibilityWebPageObjectMac.mm
    M Source/WebKit/WebProcess/WebPage/mac/WebPageMac.mm
    M Source/WebKitLegacy/mac/WebCoreSupport/WebFrameLoaderClient.h

  Log Message:
  -----------
  AX: Avoid hitting the main thread to retrieve position and size of WKAccessibilityWebPageObjects in isolated tree mode.
https://bugs.webkit.org/show_bug.cgi?id=256207
<rdar://problem/108787870>

Reviewed by Chris Dumez and Tyler Wilcock.

The WKAccessibilityWebPageObject methods accessibilityAttributePositionValue and accessibilityAttributeSizeValue are contributors to the thread contention occurring during page load while AT client is querying for accessibility data. Currently these methods always hit the main thread. With this change, we cache and update these properties and thus avoid hitting the main thread, improving responsiveness to AT clients.
In addition, this patch also allows the caching of the root of the isolated tree in WKAccessibilityWebPageObject which will be used in a follow up change.

* Source/WebCore/loader/EmptyClients.cpp:
(WebCore::EmptyFrameLoaderClient::setAXIsolatedTreeRoot):
* Source/WebCore/loader/EmptyFrameLoaderClient.h:
* Source/WebCore/loader/FrameLoaderClient.h:
* Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.cpp:
(WebKit::WebFrameLoaderClient::setAXIsolatedTreeRoot):
* Source/WebKit/WebProcess/WebCoreSupport/WebFrameLoaderClient.h:
* Source/WebKit/WebProcess/WebPage/WebPage.cpp:
(WebKit::WebPage::setSize):
(WebKit::WebPage::windowAndViewFramesChanged):
* Source/WebKit/WebProcess/WebPage/WebPage.h:
* Source/WebKit/WebProcess/WebPage/mac/WKAccessibilityWebPageObjectBase.h:
* Source/WebKit/WebProcess/WebPage/mac/WKAccessibilityWebPageObjectBase.mm:
(-[WKAccessibilityWebPageObjectBase accessibilityRootObjectWrapper]):
(-[WKAccessibilityWebPageObjectBase setWebPage:]):
(-[WKAccessibilityWebPageObjectBase setPosition:]):
(-[WKAccessibilityWebPageObjectBase setSize:]):
(-[WKAccessibilityWebPageObjectBase setIsolatedTreeRoot:]):
* Source/WebKit/WebProcess/WebPage/mac/WKAccessibilityWebPageObjectMac.mm:
(-[WKAccessibilityWebPageObject accessibilityChildren]):
(-[WKAccessibilityWebPageObject accessibilityAttributeSizeValue]):
(-[WKAccessibilityWebPageObject accessibilityAttributePositionValue]):
* Source/WebKit/WebProcess/WebPage/mac/WebPageMac.mm:
(WebKit::WebPage::cacheAXPosition):
(WebKit::WebPage::cacheAXSize):
(WebKit::WebPage::setAXIsolatedTreeRoot):
* Source/WebKitLegacy/mac/WebCoreSupport/WebFrameLoaderClient.h:

Canonical link: https://commits.webkit.org/263618@main