Propagate ResourcesChanged to template children.

Makes `Changing_Resource_In_Templated_Parent_Should_Affect_Templated_Child` pass again.

src/Avalonia.Controls/Primitives/TemplatedControl.cs

@@ -287,6 +287,21 @@ namespace Avalonia.Controls.Primitives
             return this;
         }
 
+        protected sealed override void NotifyChildResourcesChanged(ResourcesChangedEventArgs e)
+        {
+            var count = VisualChildren.Count;
+
+            for (var i = 0; i < count; ++i)
+            {
+                if (VisualChildren[i] is ILogical logical)
+                {
+                    logical.NotifyResourcesChanged(e);
+                }
+            }
+
+            base.NotifyChildResourcesChanged(e);
+        }
+
         /// <inheritdoc/>
         protected override void OnAttachedToLogicalTree(LogicalTreeAttachmentEventArgs e)
         {

src/Avalonia.Styling/StyledElement.cs

@@ -493,6 +493,28 @@ namespace Avalonia
             }
         }
 
+        /// <summary>
+        /// Notifies child controls that a change has been made to resources that apply to them.
+        /// </summary>
+        /// <param name="e">The event args.</param>
+        protected virtual void NotifyChildResourcesChanged(ResourcesChangedEventArgs e)
+        {
+            if (_logicalChildren is object)
+            {
+                var count = _logicalChildren.Count;
+
+                if (count > 0)
+                {
+                    e ??= new ResourcesChangedEventArgs();
+
+                    for (var i = 0; i < count; ++i)
+                    {
+                        _logicalChildren[i].NotifyResourcesChanged(e);
+                    }
+                }
+            }
+        }
+
         /// <summary>
         /// Called when the styled element is added to a rooted logical tree.
         /// </summary>
@@ -781,19 +803,10 @@ namespace Avalonia
                 ResourcesChanged(this, e);
             }
 
-            if (propagate && _logicalChildren is object)
+            if (propagate)
             {
-                var count = _logicalChildren.Count;
-
-                if (count > 0)
-                {
-                    e ??= new ResourcesChangedEventArgs();
-
-                    for (var i = 0; i < count; ++i)
-                    {
-                        _logicalChildren[i].NotifyResourcesChanged(e);
-                    }
-                }
+                e ??= new ResourcesChangedEventArgs();
+                NotifyChildResourcesChanged(e);
             }
         }
 

tests/Avalonia.Styling.UnitTests/StyledElementTests_Resources.cs

@@ -166,30 +166,6 @@ namespace Avalonia.Controls.UnitTests
             Assert.True(raisedOnChild);
         }
 
-        [Fact]
-        public void Adding_Resource_Should_Call_Not_Raise_ResourceChanged_On_Template_Children()
-        {
-            Border child;
-
-            var target = new ContentControl
-            {
-                Content = child = new Border(),
-                Template = ContentControlTemplate(),
-            };
-
-            var raisedOnTarget = false;
-            var raisedOnPresenter = false;
-
-            target.Measure(Size.Infinity);
-            target.ResourcesChanged += (_, __) => raisedOnTarget = true;
-            target.Presenter.ResourcesChanged += (_, __) => raisedOnPresenter = true;
-
-            target.Resources.Add("foo", "bar");
-
-            Assert.True(raisedOnTarget);
-            Assert.False(raisedOnPresenter);
-        }
-
         [Fact]
         public void Adding_Resource_To_Styles_Should_Raise_ResourceChanged()
         {