[GTK] REGRESSION: Broken scrolling on element.io with async scrolling

https://bugs.webkit.org/show_bug.cgi?id=222265

Reviewed by Carlos Garcia Campos.

Fix transform order for layer clipping in TextureMapperLayer.

No new tests.

* platform/graphics/texmap/TextureMapperLayer.cpp:
(WebCore::TextureMapperLayer::paintSelfAndChildren):


Canonical link: https://commits.webkit.org/237997@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@277855 268f45cc-cd09-0410-ab3c-d52691b4dbfc

Source/WebCore/ChangeLog

@@ -1,3 +1,17 @@
+2021-05-21  Chris Lord  <clord@igalia.com>
+
+        [GTK] REGRESSION: Broken scrolling on element.io with async scrolling
+        https://bugs.webkit.org/show_bug.cgi?id=222265
+
+        Reviewed by Carlos Garcia Campos.
+
+        Fix transform order for layer clipping in TextureMapperLayer.
+
+        No new tests.
+
+        * platform/graphics/texmap/TextureMapperLayer.cpp:
+        (WebCore::TextureMapperLayer::paintSelfAndChildren):
+
 2021-05-21  Rob Buis  <rbuis@igalia.com>
 
         Detect invalid InlinePathData in FillInlinePath

Source/WebCore/platform/graphics/texmap/TextureMapperLayer.cpp

@@ -263,10 +263,10 @@ void TextureMapperLayer::paintSelfAndChildren(TextureMapperPaintOptions& options
     bool shouldClip = m_state.masksToBounds && !m_state.preserves3D;
     if (shouldClip) {
         TransformationMatrix clipTransform;
-        clipTransform.translate(options.offset.width() + m_state.boundsOrigin.x(),
-            options.offset.height() + m_state.boundsOrigin.y());
+        clipTransform.translate(options.offset.width(), options.offset.height());
         clipTransform.multiply(options.transform);
         clipTransform.multiply(m_layerTransforms.combined);
+        clipTransform.translate(m_state.boundsOrigin.x(), m_state.boundsOrigin.y());
         options.textureMapper.beginClip(clipTransform, FloatRoundedRect(layerRect()));
 
         // If as a result of beginClip(), the clipping area is empty, it means that the intersection of the previous