Cherry-pick 266813@main (2121192). https://bugs.webkit.org/show_bug.c…

…gi?id=260021

    [GTK] Some tests in `fast/hidpi` are crashing in debug builds
    https://bugs.webkit.org/show_bug.cgi?id=260021

    Reviewed by Miguel Gomez and Carlos Garcia Campos.

    These tests are setting custom backing scale factor from JS.
    We must re-create the drawing area's backing store when it happens.

    * LayoutTests/platform/glib/TestExpectations:
    * Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp:
    (WebKit::DrawingAreaProxyCoordinatedGraphics::incorporateUpdate):

    Canonical link: https://commits.webkit.org/266813@main

LayoutTests/platform/glib/TestExpectations

@@ -3396,14 +3396,6 @@ imported/w3c/web-platform-tests/preload/preload-type-match.html [ DumpJSConsoleL
 [ Debug ] fast/dynamic/window-resize-scrollbars-test.html [ Crash ]
 [ Debug ] fast/fixed-layout/fixed-layout.html [ Crash ]
 [ Debug ] fast/forms/textarea-node-removed-from-document-crash.html [ Crash ]
-[ Debug ] fast/hidpi/broken-image-icon-hidpi.html [ Crash ]
-[ Debug ] fast/hidpi/broken-image-icon-very-hidpi.html [ Crash ]
-[ Debug ] fast/hidpi/broken-image-with-size-hidpi.html [ Crash ]
-[ Debug ] fast/hidpi/clip-text-in-hidpi.html [ Crash ]
-[ Debug ] fast/hidpi/device-scale-factor-paint.html [ Crash ]
-[ Debug ] fast/hidpi/filters-and-image-buffer-resolution.html [ Crash ]
-[ Debug ] fast/hidpi/filters-blur.html [ Crash ]
-[ Debug ] fast/hidpi/filters-hue-rotate.html [ Crash ]
 [ Debug ] fast/history/page-cache-closed-audiocontext.html [ Crash ]
 [ Debug ] fast/media/mq-resolution.html [ Crash ]
 [ Debug ] fast/picture/viewport-resize.html [ Crash ]

Source/WebKit/UIProcess/CoordinatedGraphics/DrawingAreaProxyCoordinatedGraphics.cpp

@@ -183,7 +183,7 @@ void DrawingAreaProxyCoordinatedGraphics::incorporateUpdate(UpdateInfo&& updateI
     if (updateInfo.updateRectBounds.isEmpty())
         return;
 
-    if (!m_backingStore || m_backingStore->size() != updateInfo.viewSize)
+    if (!m_backingStore || m_backingStore->size() != updateInfo.viewSize || m_backingStore->deviceScaleFactor() != updateInfo.deviceScaleFactor)
         m_backingStore = makeUnique<BackingStore>(updateInfo.viewSize, updateInfo.deviceScaleFactor, m_webPageProxy);
 
     Region damageRegion;